A230199 Sum of digits of n-th palindromic prime.

2, 3, 5, 7, 2, 2, 5, 7, 10, 11, 7, 11, 13, 14, 16, 19, 22, 23, 19, 20, 5, 7, 8, 7, 8, 10, 13, 14, 11, 16, 17, 13, 17, 16, 17, 14, 17, 19, 20, 20, 25, 19, 22, 23, 28, 29, 7, 8, 10, 13, 14, 8, 13, 13, 14, 17, 19, 22, 16, 17, 19, 23, 20, 23, 22, 25, 22, 23, 29

Offset

1,1

Links

Shyam Sunder Gupta, Table of n, a(n) for n = 1..5953

Formula

a(n) = A007953(A002385(n)). - R. J. Mathar, Sep 09 2015

Example

a(6) =2, since sum of digits of 6th palindromic prime i.e. 101 is 2.

Mathematica

a = {}; Do[z = n*10^(IntegerLength[n] - 1) +
FromDigits@Rest@Reverse@IntegerDigits[n]; If[PrimeQ[z], s = Apply[Plus, IntegerDigits[z]]; AppendTo[a, s]], {n, 1, 10^5}]; Insert[a, 2, 5]
palQ[n_]:=Module[{idn=IntegerDigits[n]}, idn==Reverse[idn]]; Total[ IntegerDigits[ #]]&/@ Select[Prime[Range[5000]], palQ] (* Harvey P. Dale, Oct 10 2014 *)

Crossrefs

Cf. A002385, A007953, A007605.

Sequence in context: A357096 A093338 A229875 * A275542 A187559 A104212

Adjacent sequences: A230196 A230197 A230198 * A230200 A230201 A230202

Keyword

nonn,base,less

Author

Shyam Sunder Gupta, Oct 11 2013

Status

approved