a(n) = Sum_{k=0..n-3} T(n,k)*T(n,k+3), T given by A026736.
A027218
a(n) = Sum_{k=0..n-3} T(n,k)*T(n,k+3), T given by A026736.
Terms
- a(0) =1a(1) =9a(2) =51a(3) =279a(4) =1277a(5) =6235a(6) =26789a(7) =125370a(8) =525082a(9) =2409886a(10) =9969722a(11) =45289767a(12) =186105280a(13) =840402559a(14) =3439358196a(15) =15472942142a(16) =63155131233a(17) =283400162019
External references
- oeis: A027218