A379689 Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(x) * (1 - x*exp(2*x)) ).
1, 0, 5, 26, 557, 9504, 254737, 7405712, 264468185, 10599167744, 484155176381, 24530813822976, 1373346539948869, 83980088153710592, 5576376312266516681, 399370804845913339904, 30695207044654060184753, 2519882221014204064727040, 220076205166821624927515893
Offset: 0
Keywords
Programs
-
PARI
a(n) = sum(k=0, n, (n-2*k-1)^k * (2*n-k)!/(k!*(n-k)!))/(n+1);
Formula
a(n) = (1/(n+1)) * Sum_{k=0..n} (n-2*k-1)^k * (2*n-k)!/(k! * (n-k)!).