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Positive odd numbers k such that both (sigma(m) - 2*m) and (2*m - sigma(m)) are never equal to k, where sigma(.) is the sum of divisors function A000203 (conjectured).
2

%I #32 Sep 08 2021 21:17:26

%S 9,13,15,21,23,27,29,33,35,43,45

%N Positive odd numbers k such that both (sigma(m) - 2*m) and (2*m - sigma(m)) are never equal to k, where sigma(.) is the sum of divisors function A000203 (conjectured).

%Y Intersection of A234285 and A234286.

%Y Inspired by _Michel Marcus_'s comment in A294347.

%Y Cf. A000203, A033879, A033880, A005100, A005101.

%K nonn,more,hard

%O 1,1

%A _Omar E. Pol_, Oct 30 2017