A077523 - OEIS

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

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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.