a(n) = 1*2*3 + 4*5*6 + 7*8*9 + 10*11*12 + 13*14*15 + 16*17*18 + ... + (up to n).

Terms

a(0) =1a(1) =2a(2) =6a(3) =10a(4) =26a(5) =126a(6) =133a(7) =182a(8) =630a(9) =640a(10) =740a(11) =1950a(12) =1963a(13) =2132a(14) =4680a(15) =4696a(16) =4952a(17) =9576a(18) =9595a(19) =9956a(20) =17556a(21) =17578a(22) =18062a(23) =29700a(24) =29725a(25) =30350a(26) =47250a(27) =47278a(28) =48062a(29) =71610