a(n) = (2*n-1)*(3*n-1)*(4*n-1).

Terms

a(0) =-1a(1) =6a(2) =105a(3) =440a(4) =1155a(5) =2394a(6) =4301a(7) =7020a(8) =10695a(9) =15470a(10) =21489a(11) =28896a(12) =37835a(13) =48450a(14) =60885a(15) =75284a(16) =91791a(17) =110550a(18) =131705a(19) =155400a(20) =181779a(21) =210986a(22) =243165a(23) =278460a(24) =317015a(25) =358974a(26) =404481a(27) =453680a(28) =506715