A077523 Central digit of palindromic primes.

0, 3, 5, 8, 9, 1, 5, 7, 8, 2, 5, 8, 9, 1, 2, 3, 5, 6, 3, 4, 4, 7, 8, 3, 8, 9, 3, 7, 4, 5, 0, 3, 5, 6, 4, 9, 1, 4, 3, 8, 9, 1, 2, 4, 7, 8, 0, 5, 3, 4, 5, 5, 8, 0, 1, 3, 7, 2, 5, 2, 5, 0, 1, 7, 2, 2, 5, 6, 3, 9, 2, 7, 0, 2, 6, 0, 7, 5, 3, 6, 3, 4, 9, 4, 7, 8, 3, 6, 9, 7, 0, 1, 2, 7, 0, 3, 6, 8, 9, 9, 2, 4, 7, 3, 5

Offset

6,2

Comments

Middle digit of terms of A002385 from 101 onwards, skipping 2, 3, 5, 7, 11 hence offset starting at 6.

Links

Table of n, a(n) for n=6..110.

P. De Geest, World!Of Palindromic Primes

Mathematica

a = {}; Do[pp = IntegerDigits[ Prime[n]]; If[pp == Reverse[pp], a = Append[a, pp[[(Length[pp] + 1)/2]]]], {n, 6, 9385}]; a

Crossrefs

Cf. A002385.

Sequence in context: A139125 A354415 A186697 * A298516 A157291 A107820

Adjacent sequences: A077520 A077521 A077522 * A077524 A077525 A077526

Keyword

base,nonn

Author

Amarnath Murthy, Nov 08 2002

Extensions

Edited and extended by Patrick De Geest, Jun 11 2003

Status

approved