Binomial transform A140456(n+1) (indecomposable involutions).

A188144

Binomial transform A140456(n+1) (indecomposable involutions).

Terms

    a(0) =1a(1) =2a(2) =6a(3) =20a(4) =74a(5) =292a(6) =1218a(7) =5308a(8) =24034a(9) =112484a(10) =542346a(11) =2686268a(12) =13639226a(13) =70863652a(14) =376208706a(15) =2038335580a(16) =11259474754a(17) =63353211332a(18) =362819139978

External references