Generalized sum of divisors function.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =14a(5) =18a(6) =28a(7) =40a(8) =52a(9) =70a(10) =88a(11) =104a(12) =140a(13) =168a(14) =196a(15) =240a(16) =278a(17) =320a(18) =380a(19) =440a(20) =504a(21) =562a(22) =644a(23) =720a(24) =808a(25) =910a(26) =1000a(27) =1120a(28) =1240a(29) =1360