A025191 a(n) = Sum_{k=0..n} T(n,k), where T is the array defined in A025177.

1, 1, 4, 11, 33, 97, 288, 855, 2544, 7577, 22590, 67399, 201215, 601017, 1795966, 5368659, 16053417, 48015873, 143649102, 429842511, 1286452725, 3850770081, 11528245602, 34517105907, 103360732956, 309543786441, 927106804368, 2776994293355

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Comments

Conjectures: a(n) = A027914(n)-A027914(n-1) = (A081673(n)-A081673(n-1))/2.

Extensions

a(1) corrected by Jason Yuen, Aug 05 2024