A308871 - OEIS

%I #7 Jun 29 2019 17:06:47

%S 0,0,0,0,0,0,1,1,2,4,7,11,19,26,40,57,81,109,153,198,264,342,442,556,

%T 710,875,1093,1338,1638,1975,2398,2855,3416,4040,4779,5595,6573,7627,

%U 8875,10244,11822,13549,15553,17707,20187,22883,25935,29239,32991,37010

%N Sum of the third largest 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)} j.

%F a(n) = A308867(n) - A308868(n) - A308869(n) - A306670(n) - A308872(n) - A308873(n).

%t Table[Sum[Sum[Sum[Sum[Sum[j, {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, 50}]

%Y Cf. A238340, A308867, A308868, A308869, A306670, A308872, A308873.

%K nonn

%O 0,9

%A _Wesley Ivan Hurt_, Jun 29 2019