Triangle, read by rows, where the n-th row lists the (2n+1) coefficients of (1+2x+2x^2)^n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =1a(5) =4a(6) =8a(7) =8a(8) =4a(9) =1a(10) =6a(11) =18a(12) =32a(13) =36a(14) =24a(15) =8a(16) =1a(17) =8a(18) =32a(19) =80a(20) =136a(21) =160a(22) =128a(23) =64a(24) =16a(25) =1a(26) =10a(27) =50a(28) =160a(29) =360