A338818 Primes p such that the sum of squares of primes < p is divisible by p.

2, 13, 59, 118259, 182603

Offset: 1

Author

J. M. Bergot and Robert Israel, Nov 10 2020

Keywords

• nonn
• more

Comments

Primes prime(n) such that A024450(n) is divisible by prime(n).

a(6) > 8 * 10^9 if it exists. - Robert Israel, Jun 10 2025

Examples

			a(3) = 59 = prime(17) is in the sequence because A024450(17)=16756 is divisible by 59.
		

Crossrefs

Cf. A007506, A024450.

Programs

Maple

P:= select(isprime, [2,seq(i,i=3..10^6,2)]):
S:= ListTools:-PartialSums(map(`^`,P,2)):
P[select(t -> S[t] mod P[t]=0, [$1..nops(P)])];

PARI

lista(nn) = {my(s=0, list=List()); forprime(p=2, nn, s += p^2; if (!(s % p), listput(list, p));); Vec(list);} \\ Michel Marcus, Nov 11 2020