Square array sigma_k(n) read down antidiagonals: sum of the k-th powers of the divisors of n.

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =5a(5) =4a(6) =1a(7) =9a(8) =10a(9) =7a(10) =1a(11) =17a(12) =28a(13) =21a(14) =6a(15) =1a(16) =33a(17) =82a(18) =73a(19) =26a(20) =12a(21) =1a(22) =65a(23) =244a(24) =273a(25) =126a(26) =50a(27) =8a(28) =1a(29) =129