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A231546 Numbers n such that sigma(n) = sigma(n-1). 3

%I

%S 15,207,958,1335,1365,1635,2686,2975,4365,14842,18874,19359,20146,

%T 24958,33999,36567,42819,56565,64666,74919,79827,79834,84135,92686,

%U 109215,111507,116938,122074,138238,147455,161002,162603,166935

%N Numbers n such that sigma(n) = sigma(n-1).

%C Also, numbers n such that n = antisigma(n) - antisigma(n-1), where antisigma(n) = A024816(n) = the sum of the non-divisors of n that are between 1 and n.

%F a(n) = A002961(n) + 1.

%e 15 = antisigma(15) - antisigma(14) = 96 - 81.

%Y Cf. A002961, A024816 (antisigma(n)), A231545 (numbers n such that antisigma(n) = antisigma(n-1)).

%K nonn

%O 1,1

%A _Jaroslav Krizek_, Nov 11 2013

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Last modified October 16 01:20 EDT 2019. Contains 328038 sequences. (Running on oeis4.)