A309550 - OEIS

%I #5 Aug 07 2019 06:59:07

%S 0,0,0,0,0,0,6,5,12,15,32,39,72,92,156,198,300,380,556,683,936,1162,

%T 1550,1887,2448,2957,3758,4495,5572,6614,8122,9528,11496,13435,16026,

%U 18563,21924,25244,29548,33821,39212,44650,51464,58244,66616,75123,85440

%N Sum of the odd parts in the partitions of n into 6 parts.

%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>

%F a(n) = Sum_{m=1..floor(n/6)} Sum_{l=m..floor((n-m)/5)} Sum_{k=l..floor((n-l-m)/4)} Sum_{j=k..floor((n-k-l-m)/3)} Sum_(i=j..floor((n-j-k-l-m)/2)} (i * (i mod 2) + j * (j mod 2) + k * (k mod 2) + l * (l mod 2) + m * (m mod 2) + (n-i-j-k-l-m) * ((n-i-j-k-l-m) mod 2)).

%t Table[Sum[Sum[Sum[Sum[Sum[i * Mod[i, 2] + j * Mod[j, 2] + k * Mod[k, 2] + l * Mod[l, 2] + m * Mod[m, 2] + (n - i - j - k - l - m) * Mod[n - i - j - k - l - m, 2], {i, j, Floor[(n - j - k - l - m)/2]}], {j, k, Floor[(n - k - l - m)/3]}], {k, l, Floor[(n - l - m)/4]}], {l, m, Floor[(n - m)/5]}], {m, Floor[n/6]}], {n, 0, 100}]

%K nonn

%O 0,7

%A _Wesley Ivan Hurt_, Aug 07 2019