proposed

approved

editing

proposed

From a(69)=1100110 on onward starts a repeating pattern of length 54. [From _- _M. F. Hasler_, Oct 16 2009]

(PARI) A152604(n, show_all=0)={my(a); for(i=1, n, if( i<8, a=i+(i>3)+(i>4), my(l3d=if(a>99, a%1000, [789, 951, 183][i-7])); while( a++, my(t=a+l3d*10^#Str(a)); forstep(d=#Str(a)-1, 0, -1, isprime(sum(j=d, d+3, t\10^j%10)) & next; a+=10^d-a%10^d-1; next(2)); break)); show_all&print1(a", ")); a} [From _\\ _M. F. Hasler_, Oct 16 2009]

Cf. A158652, A152603-..A152609.

approved

editing

editing

approved

E. Angelini, <a href="/A152136/a152136.pdf">Chiffres consecutifs dans quelques suites</a> [Cached copy, with permission]

approved

editing

From a(69)=1100110 on starts a repeating pattern of length 54. [From _M. F. Hasler (www.univ-ag.fr/~mhasler), _, Oct 16 2009]

(PARI) A152604(n, show_all=0)={my(a); for(i=1, n, if( i<8, a=i+(i>3)+(i>4), my(l3d=if(a>99, a%1000, [789, 951, 183][i-7])); while( a++, my(t=a+l3d*10^#Str(a)); forstep(d=#Str(a)-1, 0, -1, isprime(sum(j=d, d+3, t\10^j%10)) & next; a+=10^d-a%10^d-1; next(2)); break)); show_all&print1(a", ")); a} [From _M. F. Hasler (www.univ-ag.fr/~mhasler), _, Oct 16 2009]

_N. J. A. Sloane (njas(AT)research.att.com), _, Sep 23 2009

From a(69)=1100110 on starts a repeating pattern of length 54. [From M. F. Hasler (MHasler(AT)www.univ-ag.fr/~mhasler), Oct 16 2009]

(PARI) A152604(n, show_all=0)={my(a); for(i=1, n, if( i<8, a=i+(i>3)+(i>4), my(l3d=if(a>99, a%1000, [789, 951, 183][i-7])); while( a++, my(t=a+l3d*10^#Str(a)); forstep(d=#Str(a)-1, 0, -1, isprime(sum(j=d, d+3, t\10^j%10)) & next; a+=10^d-a%10^d-1; next(2)); break)); show_all&print1(a", ")); a} [From M. F. Hasler (MHasler(AT)www.univ-ag.fr/~mhasler), Oct 16 2009]

nonn,base,new

a(1) = 1; thereafter a(n) is always the smallest integer > a(n-1) not leading to a contradiction, such that any four consecutive digits in the sequence sum up to a prime.

1, 2, 3, 5, 7, 8, 9, 51, 83, 110, 111, 211, 301, 310, 311, 631, 703, 710, 911, 2111, 2113, 2117, 2119, 2153, 2155, 2159, 2171, 2173, 2177, 2179, 2513, 2515, 2519, 2531, 2533, 2537, 2539, 2573, 2575, 2579, 8513, 8515, 8519, 8573, 8579, 8591

1,2

Computed by Jean-Marc Falcoz.

From a(69)=1100110 on starts a repeating pattern of length 54. [From M. F. Hasler (MHasler(AT)univ-ag.fr), Oct 16 2009]

Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/ConsecDig.htm">Chiffres consecutifs dans quelques suites</a>

(PARI) A152604(n, show_all=0)={my(a); for(i=1, n, if( i<8, a=i+(i>3)+(i>4), my(l3d=if(a>99, a%1000, [789, 951, 183][i-7])); while( a++, my(t=a+l3d*10^#Str(a)); forstep(d=#Str(a)-1, 0, -1, isprime(sum(j=d, d+3, t\10^j%10)) & next; a+=10^d-a%10^d-1; next(2)); break)); show_all&print1(a", ")); a} [From M. F. Hasler (MHasler(AT)univ-ag.fr), Oct 16 2009]

Cf. A158652, A152603-A152609.

nonn,base

N. J. A. Sloane (njas(AT)research.att.com), Sep 23 2009

approved