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A243935
Numbers m such that 5 divides A000041(m).
8
4, 7, 9, 14, 18, 19, 23, 24, 27, 29, 34, 38, 39, 44, 49, 54, 58, 59, 61, 64, 66, 68, 69, 71, 74, 79, 82, 84, 89, 94, 97, 99, 103, 104, 109, 114, 119, 120, 124, 127, 128, 129, 130, 134, 136, 139, 140, 142, 144, 149, 154, 159, 163, 164, 165, 169, 170, 173, 174
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[200], Mod[PartitionsP[#], 5] == 0 &]
PROG
(Sage)
@CachedFunction
def A000041(n):
if n == 0: return 1
S = 0; J = n-1; k = 2
while 0 <= J:
T = A000041(J)
S = S+T if is_odd(k//2) else S-T
J -= k if is_odd(k) else k//2
k += 1
return S
[n for n in (0..200) if mod(A000041(n), 5) == 0]
(Magma) [n: n in [1..200] | IsZero(NumberOfPartitions(n) mod 5)];
(PARI) is(n)=numbpart(n)%5==0 \\ Charles R Greathouse IV, Apr 08 2015
CROSSREFS
Numbers m such that k divides A000041(m), where k is prime: A001560 (k=2), A083214 (k=3), this sequence (k=5), A243936 (k=7), A027827 (k=11), A071750 (k=13). For k composite: A237278 (k=4), A035700 (k=12).
Sequence in context: A310965 A035510 A187898 * A310966 A287559 A032778
KEYWORD
nonn,easy
AUTHOR
Bruno Berselli, Jun 15 2014
STATUS
approved