A381245 Numbers that are partial sums of the reverses of the sequence of primes and are reverses of primes.

2, 5, 17, 358, 775, 3145, 7813, 10277, 13978, 15232, 19478, 32324, 36056, 70042, 71396, 72893, 76856, 102374, 141982, 155585, 301291, 331357, 332588, 354643, 717817, 763586, 791641, 799532, 922981, 931705, 935117, 940241, 952975, 993551, 1020461, 1028383, 1060075, 1094099, 1126831, 1145257

Offset

1,1

Comments

Intersection of A071602 (in that order) and A004087.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(4) = 358 is a term because 358 = A071602(11) is the sum of the reverses of the first 11 primes, and is the reverse of the prime 853.
A071602(7) = 130 is not a term, because 130 is not the reverse of a prime, even though the reverse of 130 is a prime.

Maple

rev:= proc(n) local L, i;
  L:= convert(n, base, 10);
  add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
PR:= map(rev, select(isprime, [$1..10000])):
SPR:= ListTools:-PartialSums(PR):
select(t -> t mod 10 <> 0 and isprime(rev(t)), SPR);

Crossrefs

Cf. A004087, A071602.

Sequence in context: A376184 A348927 A081465 * A128000 A161469 A342606

Adjacent sequences: A381242 A381243 A381244 * A381246 A381247 A381248

Keyword

nonn,base

Author

Robert Israel, Feb 17 2025

Status

approved