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%I #6 Jul 02 2019 11:20:22
%S 0,0,0,0,0,0,0,1,1,3,5,10,15,27,39,61,87,128,175,249,331,450,590,779,
%T 998,1292,1628,2063,2567,3198,3923,4827,5854,7106,8538,10253,12197,
%U 14516,17126,20197,23658,27683,32197,37422,43247,49931,57382,65865,75275
%N Sum of the second largest parts in the partitions of n into 7 parts.
%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F a(n) = Sum_{o=1..floor(n/7)} Sum_{m=o..floor((n-o)/6)} Sum_{l=m..floor((n-m-o)/5)} Sum_{k=l..floor((n-l-m-o)/4)} Sum_{j=k..floor((n-k-l-m-o)/3} Sum_{i=j..floor((n-j-k-l-m-o)/2)} i.
%F a(n) = A308926(n) - A308927(n) - A308928(n) - A308929(n) - A308930(n) - A308931(n) - A308933(n).
%t Table[Sum[Sum[Sum[Sum[Sum[Sum[i, {i, j, Floor[(n - j - k - l - m - o)/2]}], {j, k, Floor[(n - k - l - m - o)/3]}], {k, l, Floor[(n - l - m - o)/4]}], {l, m, Floor[(n - m - o)/5]}], {m, o, Floor[(n - o)/6]}], {o, Floor[n/7]}], {n, 0, 50}]
%Y Cf. A026813, A308926, A308927, A308928, A308929, A308930, A308931, A308933.
%K nonn
%O 0,10
%A _Wesley Ivan Hurt_, Jun 30 2019
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