cp's OEIS Frontend

A309656 Number of odd parts in the partitions of n into 9 parts.

%I A309656 #5 Aug 12 2019 03:25:34
%S A309656 0,0,0,0,0,0,0,0,0,9,8,16,22,37,48,75,96,140,180,249,316,429,536,703,
%T A309656 876,1125,1382,1746,2122,2636,3184,3898,4668,5662,6724,8065,9522,
%U A309656 11320,13272,15660,18246,21370,24770,28812,33218,38425,44076,50692,57900,66254
%N A309656 Number of odd parts in the partitions of n into 9 parts.
%H A309656 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A309656 a(n) = Sum_{q=1..floor(n/9)} Sum_{p=q..floor((n-q)/8)} Sum_{o=p..floor((n-p-q)/7)} Sum_{m=o..floor((n-o-p-q)/6)} Sum_{l=m..floor((n-m-o-p-q)/5)} Sum_{k=l..floor((n-l-m-o-p-q)/4)} Sum_{j=k..floor((n-k-l-m-o-p-q)/3)} Sum_{i=j..floor((n-j-k-l-m-o-p-q)/2)} (q mod 2) + (p mod 2) + (o mod 2) + (m mod 2) + (l mod 2) + (k mod 2) + (j mod 2) + (i mod 2) + ((n-i-j-k-l-m-o-p-q) mod 2).
%t A309656 Table[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Mod[i, 2] + Mod[j, 2] + Mod[k, 2] + Mod[l, 2] + Mod[m, 2] + Mod[o, 2] + Mod[p, 2] + Mod[q, 2] + Mod[n - i - j - k - l - m - o - p - q, 2], {i, j, Floor[(n - j - k - l - m - o - p - q)/2]}], {j, k, Floor[(n - k - l - m - o - p - q)/3]}], {k, l, Floor[(n - l - m - o - p - q)/4]}], {l, m, Floor[(n - m - o - p - q)/5]}], {m, o, Floor[(n - o - p - q)/6]}], {o, p, Floor[(n - p - q)/7]}], {p, q, Floor[(n - q)/8]}], {q, Floor[n/9]}], {n, 0, 50}]
%K A309656 nonn
%O A309656 0,10
%A A309656 _Wesley Ivan Hurt_, Aug 11 2019