Coefficient of x^2 in expansion of (x+1)*(x+3)*...*(x+2*n-1).

A028339

Coefficient of x^2 in expansion of (x+1)*(x+3)*...*(x+2*n-1).

Terms

    a(0) =1a(1) =9a(2) =86a(3) =950a(4) =12139a(5) =177331a(6) =2924172a(7) =53809164a(8) =1094071221a(9) =24372200061a(10) =590546123298

External references