1,1

Ivan Neretin, Table of n, a(n) for n = 1..10000

{A000027} minus {A070286}.

mx = 100; Complement[Range[mx], Table[Nest[DivisorSigma[1, #] &, n, 2], {n, mx}]] (* Ivan Neretin, Feb 12 2018 *)

Complement of A070286.

Sequence in context: A230044 A069861 A047449 * A107040 A045989 A129832

Adjacent sequences: A162920 A162921 A162922 * A162924 A162925 A162926

nonn

Jaroslav Krizek, Jul 17 2009

approved