2554675200

Appears in sequences

• Expansion of tanh(log(1+1/x)).at n=11A009769
• Denominators of the coefficients of the series for InverseErf(x).at n=5A122551
• E.g.f.: -log( sqrt(1-x^2) - x ).at n=11A194349
• a(0)=1; thereafter a(n) = n*a(n-1) if n is even, otherwise a(n) = 2*n*a(n-1).at n=11A232205
• a(n) = Sum_{permutations p of [n]} des(p^2), where des(p) is the number of descents of p.at n=11A385366