a(n) = (3^n/n!) * Product_{k=0..n-1} (3*k + 2).
A004988
a(n) = (3^n/n!) * Product_{k=0..n-1} (3*k + 2).
Terms
- a(0) =1a(1) =6a(2) =45a(3) =360a(4) =2970a(5) =24948a(6) =212058a(7) =1817640a(8) =15677145a(9) =135868590a(10) =1182056733a(11) =10316131488a(12) =90266150520a(13) =791564704560
External references
- oeis: A004988