a(n) = lcm(n, n+1, n+2)/6.

Terms

a(0) =1a(1) =2a(2) =10a(3) =10a(4) =35a(5) =28a(6) =84a(7) =60a(8) =165a(9) =110a(10) =286a(11) =182a(12) =455a(13) =280a(14) =680a(15) =408a(16) =969a(17) =570a(18) =1330a(19) =770a(20) =1771a(21) =1012a(22) =2300a(23) =1300a(24) =2925a(25) =1638a(26) =3654a(27) =2030a(28) =4495a(29) =2480