Second partial sums of seventh powers (A001015).

Terms

a(0) =1a(1) =130a(2) =2446a(3) =21146a(4) =117971a(5) =494732a(6) =1695036a(7) =4992492a(8) =13072917a(9) =31153342a(10) =68720938a(11) =142120342a(12) =278268263a(13) =519829688a(14) =932250488a(15) =1613106744a(16) =2704301673a(17) =4407716634a(18) =7005003334a(19) =10882290034a(20) =16560665275a(21) =24733398404a(22) =36310956980a(23) =52474986980a(24) =74742532605a(25) =105041888406