A027226 a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026747.

1, 11, 75, 496, 2523, 14903, 68478, 389040, 1705001, 9552071, 40792260, 227758442, 957346363, 5353798598, 22267534284, 125033595506, 516148089100, 2913354375795, 11958933491775, 67884893610121, 277431526202759, 1583886793301326, 6449958580342975, 37029044240499120

Offset: 3

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 24 2019