Triangle, read by rows of 2*n+1 terms, where row n lists the coefficients in (1+3*x+2*x^2)^n.

Terms

a(0) =1a(1) =1a(2) =3a(3) =2a(4) =1a(5) =6a(6) =13a(7) =12a(8) =4a(9) =1a(10) =9a(11) =33a(12) =63a(13) =66a(14) =36a(15) =8a(16) =1a(17) =12a(18) =62a(19) =180a(20) =321a(21) =360a(22) =248a(23) =96a(24) =16a(25) =1a(26) =15a(27) =100a(28) =390a(29) =985