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A343796
a(n) is the number of distinct primes of the form A007504(n) mod p for the first n primes p.
2
0, 1, 0, 2, 1, 1, 3, 1, 2, 2, 2, 5, 2, 3, 2, 6, 5, 5, 6, 5, 5, 5, 6, 8, 4, 4, 4, 8, 6, 8, 6, 9, 10, 9, 5, 10, 7, 10, 9, 11, 9, 8, 11, 5, 11, 4, 10, 14, 9, 19, 9, 14, 9, 11, 11, 9, 9, 15, 15, 17, 10, 11, 13, 15, 8, 15, 12, 17, 15, 10, 13, 15, 14, 17, 12, 13, 12, 16, 13, 13, 18, 16, 18, 15, 15, 17
OFFSET
1,4
LINKS
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
Sequence in context: A037034 A340056 A229897 * A139462 A236256 A357217
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Apr 29 2021
STATUS
approved