a(n) = Sum_{k=0..m-3} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.
A027318
a(n) = Sum_{k=0..m-3} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.
Terms
- a(0) =1a(1) =42a(2) =420a(3) =3786a(4) =33648a(5) =297940a(6) =2633872a(7) =23265744a(8) =205446960a(9) =1814136746a(10) =16021697220a(11) =141535810130
External references
- oeis: A027318