Triangle read by rows: coefficients of 1; 1(X+2); 1(X+2)(X+3); 1(X+2)(X+3)(X+4); ....

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =5a(5) =6a(6) =1a(7) =9a(8) =26a(9) =24a(10) =1a(11) =14a(12) =71a(13) =154a(14) =120a(15) =1a(16) =20a(17) =155a(18) =580a(19) =1044a(20) =720a(21) =1a(22) =27a(23) =295a(24) =1665a(25) =5104a(26) =8028a(27) =5040a(28) =1a(29) =35