OFFSET
1,4
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(8) = 1 because A007504(8) = 77 and there is only one prime of the form 77 mod p for the first 8 primes p, namely 2 = 77 mod 3 = 77 mod 5.
MAPLE
N:= 200: # for a(1)..a(N)
P:= [seq(ithprime(i), i=1..N)]:
S:= ListTools:-PartialSums(P):
PS:= convert(P, set):
f:= proc(n)
nops(map(p -> S[n] mod p, PS[1..n]) intersect PS);
end proc:
map(f, [$1..N]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Apr 29 2021
STATUS
approved