A117781 Total number of palindromic primes in base 6 below 6^n.

3, 4, 10, 10, 31, 31, 126, 126, 571, 571, 2752, 2752, 14248, 14248, 73971, 73971, 389920, 389920, 2108414, 2108414, 11512078, 11512078

Offset

1,1

Comments

Every palindrome with an even number of digits is divisible by 11 (in base 6) and therefore is composite (not prime). Hence there is only one palindromic prime with an even number of digits.

Links

Table of n, a(n) for n=1..22.

Eric Weisstein's World of Mathematics, Palindromic Prime.

Crossrefs

Partial sums of A117782.

Cf. A029974, A117701.

Cf. A117772, A117775, A117777, A117779, A117783, A117785, A117787.

Sequence in context: A128488 A359366 A226303 * A075100 A288660 A212440

Adjacent sequences: A117778 A117779 A117780 * A117782 A117783 A117784

Keyword

nonn,base,more

Author

Martin Renner, Apr 15 2006

Extensions

a(11)-a(22) from the data at A117782 added by Amiram Eldar, Mar 21 2021

Status

approved