Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = Sum_{d|n} d^(n+k).

Terms

a(0) =1a(1) =1a(2) =5a(3) =1a(4) =9a(5) =28a(6) =1a(7) =17a(8) =82a(9) =273a(10) =1a(11) =33a(12) =244a(13) =1057a(14) =3126a(15) =1a(16) =65a(17) =730a(18) =4161a(19) =15626a(20) =47450a(21) =1a(22) =129a(23) =2188a(24) =16513a(25) =78126a(26) =282252a(27) =823544a(28) =1a(29) =257