A091923 Primes whose decimal representations interpreted in base 11 are not prime.

11, 13, 17, 19, 23, 31, 37, 41, 47, 53, 59, 71, 73, 79, 83, 97, 101, 103, 107, 109, 113, 127, 131, 137, 149, 151, 157, 163, 167, 173, 179, 181, 191, 211, 223, 229, 233, 239, 241, 251, 257, 271, 277, 283, 293, 307, 311, 313, 317, 337, 347, 349, 359, 367, 383

Offset

1,1

Comments

A090862(A049084(a(n))) = 11.

Links

Marius A. Burtea, Table of n, a(n) for n = 1..1045

Example

A000040(9)=23 in base 11 is 2*11^1 + 3*11^0 = 25 = 5^2, therefore 29 is a term.

Mathematica

Select[Prime@Range@80, ! PrimeQ@FromDigits[IntegerDigits@#, 11] &] (* Vincenzo Librandi, Jul 01 2019 *)

Prog

(Magma) [n:n in PrimesUpTo(400)| not IsPrime(Seqint(Intseq(n), 11))]; // Marius A. Burtea, Jun 30 2019
(PARI) isok(p) = isprime(p) && (d=digits(p)) && !isprime(fromdigits(d, 11)); \\ Michel Marcus, Jun 30 2019

Crossrefs

Cf. A091924.

Sequence in context: A293660 A046117 A240900 * A046501 A050719 A217062

Adjacent sequences: A091920 A091921 A091922 * A091924 A091925 A091926

Keyword

nonn,base

Author

Reinhard Zumkeller, Feb 13 2004

Extensions

Corrected by Zak Seidov, Feb 25 2004

Status

approved