A235377 Positions of 10s in A235354.

56, 57, 69, 78, 83, 89, 92, 95, 104, 109, 111, 123, 124, 128, 136, 139, 142, 158, 160, 171, 173, 176, 177, 178, 180, 185, 194, 200, 201, 203, 211, 214, 219, 222, 223, 228, 231, 236, 237, 241, 245, 246, 248, 256, 259, 270, 274, 280, 281, 296, 298, 302, 307, 314

Offset

1,1

Comments

If prime(a(n)) is written in base k>=2, and the k-representation is read in decimal, then all such numbers, for k = 2,3,...,9, are composite.

Links

Table of n, a(n) for n=1..54.

Prog

(PARI) isok(n) = {my(p = prime(n)); for (b = 2, 9, if (isprime(subst(Pol(digits(p, b)), x, 10)), return(0)); ); return (1); } \\ Michel Marcus, Jan 18 2014

Crossrefs

Cf. A052033, A235354, A235376, A236174, A236437.

Sequence in context: A008942 A133898 A244357 * A003897 A345493 A031319

Adjacent sequences: A235374 A235375 A235376 * A235378 A235379 A235380

Keyword

nonn,base

Author

Vladimir Shevelev and Peter J. C. Moses, Jan 08 2014

Status

approved