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A116491 Number of partitions of n into distinct evil numbers. 3

%I #14 Sep 11 2019 06:39:47

%S 1,0,0,1,0,1,1,0,1,2,1,1,2,1,2,4,1,3,5,2,5,5,3,7,7,5,8,10,7,11,13,8,

%T 16,17,12,20,20,17,26,26,22,31,34,30,40,43,37,51,54,48,64,66,62,80,83,

%U 78,98,103,98,121,128,122,150,158,149,184,193,185,226,233,228,275,285,280

%N Number of partitions of n into distinct evil numbers.

%H Andrew Howroyd, <a href="/A116491/b116491.txt">Table of n, a(n) for n = 0..1000</a>

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%F Weigh Transform of characteristic function of A001969.

%p g:= proc(n) option remember; is(add(i, i=Bits[Split](n))::even) end:

%p b:= proc(n, i) option remember; `if`(i*(i+1)/2<n, 0, `if`(n=0, 1,

%p b(n, i-1)+`if`(g(i), b(n-i, min(n-i, i-1)), 0)))

%p end:

%p a:= n-> b(n$2):

%p seq(a(n), n=0..100); # _Alois P. Heinz_, Sep 08 2019

%t m = 100;

%t Product[If[EvenQ[DigitCount[k, 2, 1]], 1 + x^k, 1], {k, 1, m}] + O[x]^m // CoefficientList[#, x]& (* _Jean-François Alcover_, Sep 11 2019, from PARI *)

%o (PARI) seq(n)=Vec(prod(k=1, n, if(hammingweight(k)%2==0, 1+x^k, 1) + O(x*x^n))) \\ _Andrew Howroyd_, Jun 22 2018

%Y Cf. A067591, A116492.

%K nonn

%O 0,10

%A _Christian G. Bower_, Feb 17 2006

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Last modified April 18 18:49 EDT 2024. Contains 371781 sequences. (Running on oeis4.)