a(n) = 781250*n^2 - 455000*n + 66249.

Terms

a(0) =392499a(1) =2281249a(2) =5732499a(3) =10746249a(4) =17322499a(5) =25461249a(6) =35162499a(7) =46426249a(8) =59252499a(9) =73641249a(10) =89592499a(11) =107106249a(12) =126182499a(13) =146821249a(14) =169022499a(15) =192786249a(16) =218112499a(17) =245001249a(18) =273452499a(19) =303466249a(20) =335042499a(21) =368181249a(22) =402882499a(23) =439146249a(24) =476972499