a(n) = Sum_{k=1..n-2} T(n,k) * T(n,k+2), with T given by A026703.

A027254

a(n) = Sum_{k=1..n-2} T(n,k) * T(n,k+2), with T given by A026703.

Terms

    a(0) =1a(1) =10a(2) =62a(3) =384a(4) =1999a(5) =11214a(6) =55349a(7) =298990a(8) =1442299a(9) =7649710a(10) =36470860a(11) =191481848a(12) =906843279a(13) =4732185974a(14) =22320602389a(15) =116024453570a(16) =545848582951

External references