Triangle T(n,k) defined by Sum_{n >= 0,m >= 0} T(n,m)*x^m*y^n = 1 + y*(1 + 3*x - 4*x^2*y - 3*x^2*y^2 - 3*x^3*y^2 + 4*x^4*y^3)/((1 - y - 2*x*y - x*y^2 + x^3*y^3)*(1 - x*y)).
A061702
Triangle T(n,k) defined by Sum_{n >= 0,m >= 0} T(n,m)*x^m*y^n = 1 + y*(1 + 3*x - 4*x^2*y - 3*x^2*y^2 - 3*x^3*y^2 + 4*x^4*y^3)/((1 - y - 2*x*y - x*y^2 + x^3*y^3)*(1 - x*y)).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =1a(4) =6a(5) =5a(6) =1a(7) =9a(8) =18a(9) =6a(10) =1a(11) =12a(12) =42a(13) =44a(14) =9a(15) =1a(16) =15a(17) =75a(18) =145a(19) =95a(20) =13a(21) =1a(22) =18a(23) =117a(24) =336a(25) =420a(26) =192a(27) =20a(28) =1a(29) =21
External references
- oeis: A061702