a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026659.

A026979

a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026659.

Terms

    a(0) =1a(1) =10a(2) =75a(3) =372a(4) =2082a(5) =9382a(6) =49135a(7) =205900a(8) =1089140a(9) =4503138a(10) =22149416a(11) =89553324a(12) =466147593a(13) =1880356006a(14) =9068681952a(15) =36243551268a(16) =187297716687a(17) =748569870492

External references