%I #13 Jul 24 2021 18:18:18

%S 2,6,30,210,2310,233310,30563610,4615105110,835334024910,

%T 159548798757810,49938774011194530,17628387225951669090,

%U 6575388435279972570570,2518373770712229494528310

%N Denominator of sum of reciprocals of first n palindromic primes.

%H Vincenzo Librandi, <a href="/A046853/b046853.txt">Table of n, a(n) for n = 1..100</a>

%e 1/2 + 1/3 + 1/5 + 1/7 + 1/11 + 1/101 + ... gives 1/2, 5/6, 31/30, 247/210, ...

%t palQ[n_]:=Module[{idn=IntegerDigits[n]},idn==Reverse[idn]]; Denominator[Accumulate[1/#&/@Select[Prime[Range[100]],palQ]] (* _Vincenzo Librandi_, Dec 30 2011 *)

%t Accumulate[1/Select[Prime[Range[100]],PalindromeQ]]//Denominator (* _Harvey P. Dale_, Jul 24 2021 *)

%Y Cf. A046852, A002385.

%K nonn,base,easy

%O 1,1

%A _G. L. Honaker, Jr._

%E More terms from _Erich Friedman_, Jun 03 2001