a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026659.
A026977
a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026659.
Terms
- a(0) =1a(1) =4a(2) =24a(3) =90a(4) =365a(5) =1376a(6) =7365a(7) =28002a(8) =121049a(9) =465004a(10) =2437089a(11) =9396986a(12) =41758527a(13) =162167568a(14) =842470494a(15) =3277804402a(16) =14798196587a(17) =57865149612a(18) =299015494394
External references
- oeis: A026977