a(n) = 1+(n+1)^2+n!+Sum_{k=1..n-1} binomial(n,k)*n!/(n-k)!.
A274294
a(n) = 1+(n+1)^2+n!+Sum_{k=1..n-1} binomial(n,k)*n!/(n-k)!.
Terms
- a(0) =3a(1) =6a(2) =16a(3) =50a(4) =234a(5) =1582a(6) =13376a(7) =130986a(8) =1441810a(9) =17572214a(10) =234662352a(11) =3405357826a(12) =53334454586a(13) =896324308830
External references
- oeis: A274294