O.g.f.: Sum_{n>=0} x^n * Product_{k=1..n} (k*(k+1)/2 + x) / (1 + k*(k+1)/2*x).
A230740
O.g.f.: Sum_{n>=0} x^n * Product_{k=1..n} (k*(k+1)/2 + x) / (1 + k*(k+1)/2*x).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =10a(4) =51a(5) =370a(6) =3691a(7) =48525a(8) =812089a(9) =16832928a(10) =422860609a(11) =12649706416a(12) =444120983433
External references
- oeis: A230740