Numerator of (n-1)*n*(n+1)/12.

Terms

a(0) =0a(1) =1a(2) =2a(3) =5a(4) =10a(5) =35a(6) =28a(7) =42a(8) =60a(9) =165a(10) =110a(11) =143a(12) =182a(13) =455a(14) =280a(15) =340a(16) =408a(17) =969a(18) =570a(19) =665a(20) =770a(21) =1771a(22) =1012a(23) =1150a(24) =1300a(25) =2925a(26) =1638a(27) =1827a(28) =2030a(29) =4495