MacMahon's generalized sum of divisors function.

Terms

a(0) =1a(1) =3a(2) =9a(3) =22a(4) =42a(5) =81a(6) =140a(7) =231a(8) =351a(9) =551a(10) =783a(11) =1134a(12) =1546a(13) =2142a(14) =2835a(15) =3758a(16) =4818a(17) =6237a(18) =7826a(19) =9885a(20) =12159a(21) =14974a(22) =18261a(23) =22113a(24) =26511a(25) =31668a(26) =37611a(27) =44149a(28) =52074a(29) =60660