Triangle of coefficients of (x+1)*(x+3)*(x+6)*...*(x+n(n+1)/2).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =3a(6) =1a(7) =10a(8) =27a(9) =18a(10) =1a(11) =20a(12) =127a(13) =288a(14) =180a(15) =1a(16) =35a(17) =427a(18) =2193a(19) =4500a(20) =2700a(21) =1a(22) =56a(23) =1162a(24) =11160a(25) =50553a(26) =97200a(27) =56700a(28) =1a(29) =84