The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A239114

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Exponent of 2 in prime factorization (i.e., 2-adic valuation) of odd nonprimes A014076(n) + 1.
(history; published version)

#10 by Ralf Stephan at Sat Mar 15 05:29:25 EDT 2014

STATUS

proposed

approved

#9 by Michel Marcus at Thu Mar 13 06:58:40 EDT 2014

STATUS

editing

proposed

Discussion

Thu Mar 13

13:48

K. G. Stier: Thanks to Michel Marcus for adding the program.

#8 by Michel Marcus at Thu Mar 13 06:58:36 EDT 2014

PROG

(PARI) lista(nn) = {forstep(n=1, nn, 2, if (! isprime(n), print1(valuation(n+1, 2), ", ")); ); } \\ Michel Marcus, Mar 13 2014

STATUS

proposed

editing

#7 by Jon E. Schoenfield at Wed Mar 12 22:51:38 EDT 2014

STATUS

editing

proposed

#6 by Jon E. Schoenfield at Wed Mar 12 22:51:36 EDT 2014

NAME

Exponent of 2 in prime factorization (i.e. , 2-adic valuation) of odd nonprimes A014076(n) + 1.

COMMENTS

Sequence is counterpart to A023512, i.e. , merging these two sequences gives the ruler function A001511.

CROSSREFS

Cf. A023512, A001511, A014076.

STATUS

proposed

editing

#5 by K. G. Stier at Mon Mar 10 13:03:10 EDT 2014

STATUS

editing

proposed

Discussion

Tue Mar 11

03:27

Joerg Arndt: A program would be welcome.

06:23

K. G. Stier: I know. Maybe there's someone who is interested to add a program, since I don't have MAGMA, PARI etc., unfortunately. For this sequence programs weren't necessary though, as the values can be easily calculated from already existing ones (see formula).

Wed Mar 12

13:53

Joerg Arndt: Get Pari, it's just a download away!  (Also, for heavy symbolic tasks, grab Sage).

#4 by K. G. Stier at Mon Mar 10 13:03:04 EDT 2014

LINKS

K. G. Stier, <a href="/A239114/b239114.txt">Table of n, a(n) for n = 1..7739</a>

STATUS

proposed

editing

#3 by K. G. Stier at Mon Mar 10 13:01:20 EDT 2014

STATUS

editing

proposed

#2 by K. G. Stier at Mon Mar 10 12:59:33 EDT 2014

NAME

allocated for K. G. Stier

Exponent of 2 in prime factorization (i.e. 2-adic valuation) of odd nonprimes A014076(n) + 1.

DATA

1, 1, 4, 1, 1, 2, 1, 2, 3, 1, 1, 2, 3, 1, 6, 1, 1, 2, 1, 1, 1, 3, 2, 1, 5, 2, 1, 4, 2, 1, 3, 1, 2, 1, 1, 1, 3, 1, 4, 1, 2, 1, 2, 5, 1, 1, 1, 2, 4, 1, 3, 1, 2, 1, 2, 1, 2, 1, 4, 1, 1, 3, 1, 2, 1, 1, 3, 2, 1, 2, 1, 3, 1, 1, 8, 2, 1, 1, 2, 1, 2, 3, 1, 5, 1, 2, 3, 1, 2, 1, 4, 1, 1, 2, 6, 1, 2, 1, 3, 1

OFFSET

1,3

COMMENTS

Sequence is counterpart to A023512, i.e. merging these two sequences gives the ruler function A001511.

FORMULA

a(n) = A001511((A014076(n)+1)/2)

EXAMPLE

a(13) = 3, because the 13th odd nonprime is 55, and the largest power of 2 dividing 55+1 is 3.

CROSSREFS

Cf. A023512, A001511, A014076

KEYWORD

allocated

nonn

AUTHOR

K. G. Stier, Mar 10 2014

STATUS

approved

editing

#1 by K. G. Stier at Mon Mar 10 12:59:33 EDT 2014

NAME

allocated for K. G. Stier

KEYWORD

allocated

STATUS

approved