a(n) = floor( n*(n-1)*(n-2)/23 ).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =2a(6) =5a(7) =9a(8) =14a(9) =21a(10) =31a(11) =43a(12) =57a(13) =74a(14) =94a(15) =118a(16) =146a(17) =177a(18) =212a(19) =252a(20) =297a(21) =346a(22) =401a(23) =462a(24) =528a(25) =600a(26) =678a(27) =763a(28) =854a(29) =953