G.f.: exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^3 * x^k] * x^n/n ), an integer series in x.
A166896
G.f.: exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^3 * x^k] * x^n/n ), an integer series in x.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =16a(5) =45a(6) =142a(7) =459a(8) =1508a(9) =5122a(10) =17787a(11) =62649a(12) =223971a(13) =811339a(14) =2970032a(15) =10974150a(16) =40893393a(17) =153512844a(18) =580082454a(19) =2205046961a(20) =8427087958a(21) =32362949488a(22) =124837337235a(23) =483508287359
External references
- oeis: A166896