login
Search: a053999 -id:a053999
     Sort: relevance | references | number | modified | created      Format: long | short | data
Prime number spiral (clockwise, North spoke).
+10
9
2, 3, 31, 107, 241, 443, 709, 1049, 1471, 1973, 2539, 3191, 3911, 4729, 5651, 6637, 7699, 8867, 10133, 11503, 12941, 14537, 16073, 17863, 19727, 21601, 23609, 25759, 27967, 30319, 32719, 35201, 37831, 40627, 43391, 46399, 49411, 52553, 55813
OFFSET
0,1
COMMENTS
Smallest prime in n-th shell of prime spiral.
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is North, clockwise.
Shell 1 comprises the primes 3 5 7 11 13 17 19 23; 3 is lowest, 23 is highest.
The wheel may be rotated, but the sequences though pointing in different directions, will remain the same.
LINKS
Hermetic Systems, Prime Number Spiral.
FORMULA
a(n) = A000040(A054552(n)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at zero, proceed clockwise, North.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 - 3n + 1], {n, 0, 40} ]
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Robert G. Wilson v, Feb 25 2002
STATUS
approved
Prime number spiral (clockwise, Northeast spoke).
+10
9
2, 5, 41, 127, 269, 467, 751, 1093, 1523, 2027, 2621, 3299, 4007, 4861, 5749, 6763, 7867, 9041, 10273, 11719, 13121, 14723, 16319, 18061, 19963, 21851, 23857, 26021, 28289, 30661, 33029, 35531, 38201, 40993, 43759, 46751, 49789, 52957, 56197
OFFSET
0,1
COMMENTS
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is Northeast, clockwise.
LINKS
FORMULA
a(n) = A000040(A054554(n+1)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, Northeast.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 - 10n + 7], {n, 1, 40} ]
PROG
(Magma) [NthPrime(4*n^2 - 10*n + 7): n in [1..40]]; // Vincenzo Librandi, Aug 29 2018
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Robert G. Wilson v, Feb 25 2002
STATUS
approved
Prime number spiral (clockwise, East spoke).
+10
9
2, 7, 47, 139, 283, 503, 797, 1151, 1579, 2089, 2689, 3361, 4099, 4967, 5861, 6883, 8011, 9199, 10457, 11903, 13313, 14887, 16547, 18269, 20161, 22091, 24083, 26297, 28573, 30941, 33347, 35899, 38593, 41299, 44111, 47149, 50131, 53327, 56597
OFFSET
0,1
COMMENTS
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is East, clockwise.
LINKS
FORMULA
a(n) = A000040(A054556(n+1)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, East.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 - 9n + 6], {n, 1, 40} ]
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, and G. L. Honaker, Jr., Apr 10 2000
EXTENSIONS
Edited by Robert G. Wilson v, Feb 25 2002
STATUS
approved
Prime number spiral (clockwise, South spoke).
+10
9
2, 13, 67, 173, 347, 577, 877, 1249, 1697, 2243, 2833, 3541, 4289, 5179, 6131, 7159, 8293, 9473, 10799, 12251, 13709, 15289, 16987, 18749, 20681, 22619, 24671, 26839, 29129, 31541, 33911, 36559, 39217, 41981, 44839, 47903, 50989, 54163, 57347
OFFSET
0,1
COMMENTS
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is South, clockwise.
LINKS
FORMULA
a(n) = A000040(A054567(n+1)). - Omar E. Pol, Feb 20 2022
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, South.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 - 7n + 4], {n, 1, 40} ]
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Robert G. Wilson v, Feb 25 2002
STATUS
approved
Prime number spiral (clockwise, Southeast spoke).
+10
8
2, 11, 59, 157, 313, 547, 829, 1201, 1621, 2153, 2749, 3463, 4217, 5059, 6011, 7001, 8167, 9343, 10631, 12071, 13513, 15107, 16759, 18481, 20399, 22343, 24371, 26591, 28807, 31231, 33617, 36229, 38891, 41647, 44501, 47533, 50549, 53759, 56957
OFFSET
0,1
COMMENTS
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is Southeast, clockwise.
LINKS
FORMULA
a(n) = A000040(A053755(n)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, Southeast.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 + 1], {n, 0, 40} ]
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Frank Ellermann, Feb 24 2002
STATUS
approved
Prime number spiral (clockwise, West spoke).
+10
8
2, 19, 83, 199, 389, 641, 967, 1361, 1823, 2377, 3001, 3709, 4517, 5419, 6353, 7477, 8623, 9791, 11159, 12577, 14083, 15667, 17417, 19273, 21149, 23063, 25229, 27431, 29683, 32183, 34543, 37171, 39877, 42641, 45599, 48673, 51719, 54973, 58171
OFFSET
0,1
LINKS
FORMULA
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is West, clockwise.
a(n) = A000040(A033951(n)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, West.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 + 3n + 1], {n, 0, 40} ]
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Frank Ellermann, Feb 24 2002
STATUS
approved
Prime number spiral (clockwise, Southwest spoke).
+10
7
2, 17, 73, 191, 367, 607, 919, 1297, 1753, 2309, 2909, 3623, 4421, 5303, 6257, 7307, 8447, 9643, 10979, 12421, 13883, 15467, 17203, 19037, 20921, 22853, 24953, 27091, 29389, 31859, 34267, 36847, 39551, 42307, 45233, 48311, 51407, 54547, 57781
OFFSET
0,1
LINKS
FORMULA
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is Southwest, clockwise.
a(n) = A000040(A054569(n+1)). - R. J. Mathar, Aug 29 2018
EXAMPLE
Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, Southwest.
From Omar E. Pol, Feb 19 2022: (Start)
The spiral with four terms in every spoke looks like this:
.
227 101--103--107--109--113--127
| | |
223 97 29---31---37---41 131
| | | | |
211 89 23 3----5 43 137
| | | | | | |
199 83 19 2 7 47 139
| | | | | |
197 79 17---13---11 53 149
| | | |
193 73---71---67---61---59 151
| |
191--181--179--173--167--163--157
.
(End)
MATHEMATICA
Table[ Prime[4n^2 - 6n + 3], {n, 1, 40} ]
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Edited by Robert G. Wilson v, Feb 25 2002
STATUS
approved
Product of primes in n-th shell of prime spiral.
+10
1
2, 111546435, 10334565887047481278774629361, 36134787795296163821030157447828794735407577182650673, 83897624105100872650777504146410004512537400341032979607327005665751086721210969
OFFSET
0,1
COMMENTS
Write primes in a spiral: the first shell contains a single prime, 2. The next shell contains 8 primes, etc.
EXAMPLE
a(2)=3*5*7*11*13*17*19*23=111546435, the product of the 2nd through 9th primes.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Apr 06 2000
EXTENSIONS
a(5) corrected by Sean A. Irvine, Jan 16 2022
STATUS
approved

Search completed in 0.005 seconds