A243936 Numbers m such that 7 divides A000041(m).

5, 10, 11, 12, 16, 18, 19, 24, 26, 27, 33, 37, 39, 40, 41, 47, 48, 52, 53, 54, 55, 61, 68, 75, 76, 82, 83, 89, 96, 97, 103, 110, 111, 117, 124, 125, 131, 138, 140, 145, 147, 152, 159, 166, 170, 173, 177, 180, 187, 191, 194, 201, 208, 213, 215, 222, 225, 229, 232

Offset

1,1

Links

Bruno Berselli, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[250], Mod[PartitionsP[#], 7] == 0 &]

Prog

(Sage)
# From Peter Luschny in A000041
@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..250) if mod(A000041(n), 7) == 0]
(Magma) [n: n in [1..250] | IsZero(NumberOfPartitions(n) mod 7)];
(PARI) is(n)=numbpart(n)%7==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), A243935 (k=5), this sequence (k=7), A027827 (k=11), A071750 (k=13). For k composite: A237278 (k=4), A035700 (k=12).

Sequence in context: A262665 A106792 A232487 * A257263 A134002 A028760

Adjacent sequences: A243933 A243934 A243935 * A243937 A243938 A243939

Keyword

nonn,easy

Author

Bruno Berselli, Jun 15 2014

Status

approved