A383136 a(n) = Sum_{k=0..n} k^2 * 2^(n-k) * binomial(n,k).

0, 1, 8, 45, 216, 945, 3888, 15309, 58320, 216513, 787320, 2814669, 9920232, 34543665, 119042784, 406552365, 1377495072, 4634696961, 15496819560, 51526925037, 170465015160, 561372288561, 1841022163728, 6014703091725, 19581781196016, 63546645708225, 205608702558168

Offset: 0

Author

Seiichi Manyama, Apr 17 2025

Keywords

• nonn
• easy

Crossrefs

Cf. A027471, A383137, A383138, A383139.

Programs

PARI

a(n) = 3^(n-2)*n*(2+n);

Formula

a(n) = 3^(n-2) * n * (2 + n).