A027278 a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A026568.

2, 8, 60, 312, 2030, 11752, 74174, 450292, 2829898, 17572000, 110733420, 695885000, 4403631638, 27874477216, 177101756296, 1126506215424, 7182056699722, 45847087891480, 293141734241436, 1876495434801400, 12026885684352138, 77161051350902456, 495534832203481122

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 26 2019