A308872 Sum of the second largest parts in the partitions of n into 6 parts.

0, 0, 0, 0, 0, 0, 1, 1, 3, 5, 10, 15, 27, 37, 59, 82, 120, 160, 227, 293, 396, 508, 664, 832, 1068, 1314, 1650, 2012, 2477, 2980, 3628, 4314, 5178, 6111, 7250, 8477, 9975, 11566, 13483, 15543, 17970, 20577, 23646, 26907, 30712, 34785, 39469, 44472, 50217

Offset: 0

Author

Wesley Ivan Hurt, Jun 29 2019

Keywords

• nonn

Links

• Index entries for sequences related to partitions

Crossrefs

Cf. A238340, A308867, A308868, A308869, A306670, A306671, A308873.

Programs

Mathematica

Table[Sum[Sum[Sum[Sum[Sum[i, {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}]

Formula

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.

a(n) = A308867(n) - A308868(n) - A308869(n) - A306670(n) - A306671(n) - A308873(n).