A071602 Sum of the reverses of the first n primes.

2, 5, 10, 17, 28, 59, 130, 221, 253, 345, 358, 431, 445, 479, 553, 588, 683, 699, 775, 792, 829, 926, 964, 1062, 1141, 1242, 1543, 2244, 3145, 3456, 4177, 4308, 5039, 5970, 6911, 7062, 7813, 8174, 8935, 9306, 10277, 10458, 10649, 11040, 11831

Offset: 1

Author

Joseph L. Pe, Jun 02 2002

Keywords

• base
• easy
• nonn

Examples

			a(6) = reverse(2) + reverse(3) + reverse(5) + reverse(7) + reverse(11) + reverse(13) = 2 + 3 + 5 + 7 + 11 + 31 = 59.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• Carlos Rivera, Puzzle 178. Shallit Minimal Primes Set, The Prime Puzzles & Problems Connection.
• Jeffrey Shallit, Minimal Primes, Journal of Recreational Mathematics, vol. 30.2 1999-2000 pp. 113-117, Baywood NY.

Crossrefs

Cf. A007504, A114835.

Partial sums of A004087.

Programs

Maple

rev:= proc(n) local L,i;
  L:= convert(n,base,10);
  add(L[-i]*10^(i-1),i=1..nops(L))
end proc:
ListTools:-PartialSums(map(rev, [seq(ithprime(i),i=1..200)])); # Robert Israel, Feb 17 2025

Mathematica

f[n_] := Sum[ FromDigits[ Reverse[ IntegerDigits[Prime[i]]]], {i, 1, n}]; Table[ f[n], {n, 1, 50}]
Accumulate[FromDigits[Reverse[IntegerDigits[ #]]] & /@ Prime[Range[ 50]]]  (* Harvey P. Dale, Jan 27 2011 *)
Accumulate[IntegerReverse[Prime[Range[50]]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 10 2020 *)

PARI

a(k) = my(v=primes(n)); sum(i=1, n, fromdigits(Vecrev(digits(v[i])))); \\ Michel Marcus, Feb 17 2025

Python

from sympy import primerange
from itertools import accumulate
print(list(accumulate(int(str(p)[::-1]) for p in primerange(2, 198)))) # Michael S. Branicky, Jun 24 2022

Extensions

Edited by Robert G. Wilson v, Jun 07 2002