G.f.: Sum_{n>=0} Product_{k=1..n} ((1+x)^(3*k-2) - 1).
A207570
G.f.: Sum_{n>=0} Product_{k=1..n} ((1+x)^(3*k-2) - 1).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =34a(4) =410a(5) =6455a(6) =125251a(7) =2888305a(8) =77157780a(9) =2342972405a(10) =79701049425
External references
- oeis: A207570