G.f. A(x) satisfies A(x) = (1 + x)^3 * B(x*A(x)), where B(x) is the g.f. of A001764.
A381939
G.f. A(x) satisfies A(x) = (1 + x)^3 * B(x*A(x)), where B(x) is the g.f. of A001764.
Terms
- a(0) =1a(1) =4a(2) =13a(3) =74a(4) =568a(5) =4872a(6) =44576a(7) =425936a(8) =4199616a(9) =42404096a(10) =436238592a(11) =4556085248a(12) =48179319808a(13) =514825553408
External references
- oeis: A381939