a(n) = ( (2^n / n!) * Product_{k=0..n-1} (4*k + 1) )^2.

A127776

a(n) = ( (2^n / n!) * Product_{k=0..n-1} (4*k + 1) )^2.

Terms

    a(0) =1a(1) =4a(2) =100a(3) =3600a(4) =152100a(5) =7033104a(6) =344622096a(7) =17582760000a(8) =924193822500

External references