Expansion of (1+x^2*C^2)*C^4, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.

A071723

Expansion of (1+x^2*C^2)*C^4, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.

Terms

    a(0) =1a(1) =4a(2) =15a(3) =54a(4) =192a(5) =682a(6) =2431a(7) =8710a(8) =31382a(9) =113696a(10) =414086a(11) =1515516a(12) =5571750a(13) =20569590a(14) =76228095a(15) =283481670a(16) =1057628550a(17) =3957577800a(18) =14849601090a(19) =55859886420a(20) =210622646520a(21) =795898303668

External references