OFFSET
0,3
MATHEMATICA
Table[Length@Flatten[Permutations/@IntegerPartitions[n, 2, Join[{1}, Prime@Range@PrimePi@n]], 1], {n, 0, 80}] (* Giorgos Kalogeropoulos, Sep 12 2021 *)
PROG
(PARI) { a(n) = local(s(n) = if(n<2, 1, isprime(n))); if(n==0, 1, sum(i=1, n, s(i)*s(n-i))); } \\ Christian Krause, Dec 06 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 11 2021
STATUS
approved