A046852 Numerator of sum of reciprocals of first n palindromic primes.

1, 5, 31, 247, 2927, 297937, 39263057, 5959285217, 1083245729387, 207735268337827, 65180687788497661, 23058721563350868863, 8618531530355825754989, 3307472964561561236731357

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..100

Example

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

Mathematica

palQ[n_]:=Module[{idn=IntegerDigits[n]}, idn==Reverse[idn]]; Numerator[ Accumulate[1/#&/@Select[Prime[Range[200]], palQ]]] (* Harvey P. Dale, Dec 21 2011 *)

Crossrefs

Cf. A046853, A002385.

Sequence in context: A276312 A375525 A024451 * A375533 A361408 A056541

Adjacent sequences: A046849 A046850 A046851 * A046853 A046854 A046855

Keyword

nonn,frac,base

Author

G. L. Honaker, Jr.

Extensions

More terms from Erich Friedman, Jun 03 2001

Status

approved