Triangular array T(n,k) read by rows, where T(n,k) = coefficient of x^n*y^k in 1/(1-x-y-(x+y)^2).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =2a(6) =3a(7) =9a(8) =9a(9) =3a(10) =5a(11) =20a(12) =30a(13) =20a(14) =5a(15) =8a(16) =40a(17) =80a(18) =80a(19) =40a(20) =8a(21) =13a(22) =78a(23) =195a(24) =260a(25) =195a(26) =78a(27) =13a(28) =21a(29) =147