G.f.: A(x,y) = Sum_{n>=0} x^n * ((1+x)^n + y)^n, where A(0) = 0, as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y) = Sum_{n>=0} x^n * Sum_{k=0..n} T(n,k)*x^n*y^k, read by rows.
A325580
G.f.: A(x,y) = Sum_{n>=0} x^n * ((1+x)^n + y)^n, where A(0) = 0, as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y) = Sum_{n>=0} x^n * Sum_{k=0..n} T(n,k)*x^n*y^k, read by rows.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =1a(6) =5a(7) =7a(8) =3a(9) =1a(10) =16a(11) =24a(12) =15a(13) =4a(14) =1a(15) =57a(16) =98a(17) =67a(18) =26a(19) =5a(20) =1a(21) =231a(22) =430a(23) =336a(24) =144a(25) =40a(26) =6a(27) =1a(28) =1023a(29) =2062
External references
- oeis: A325580