Expansion of (1 + x^2*C)*C^2, where C = (1 - sqrt(1-4*x))/(2*x) is g.f. for Catalan numbers, A000108.
A071717
Expansion of (1 + x^2*C)*C^2, where C = (1 - sqrt(1-4*x))/(2*x) is g.f. for Catalan numbers, A000108.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =17a(4) =51a(5) =160a(6) =519a(7) =1727a(8) =5863a(9) =20228a(10) =70720a(11) =250002a(12) =892126a(13) =3209328a(14) =11626385a(15) =42378075a(16) =155307615a(17) =571925820a(18) =2115257100a(19) =7853744910a(20) =29263124250a(21) =109384710240a(22) =410075910270
External references
- oeis: A071717