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A326469
Sum of the fifth largest parts of the partitions of n into 9 parts.
9
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 5, 8, 13, 19, 29, 42, 60, 83, 117, 158, 216, 288, 383, 500, 655, 840, 1080, 1371, 1734, 2172, 2718, 3364, 4157, 5099, 6235, 7574, 9184, 11059, 13294, 15895, 18955, 22501, 26657, 31432, 36991, 43368, 50731, 59138, 68811
OFFSET
0,12
FORMULA
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)} l.
a(n) = A326464(n) - A326465(n) - A326466(n) - A326467(n) - A326468(n) - A326470(n) - A326471(n) - A326472(n) - A326473(n).
MATHEMATICA
Table[Sum[Sum[Sum[Sum[Sum[Sum[Sum[Sum[l, {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}]
Table[Total[IntegerPartitions[n, {9}][[All, -5]]], {n, 0, 60}] (* Harvey P. Dale, Nov 07 2020 *)
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jul 10 2019
STATUS
approved