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A192268 Anti-abundant numbers. 8

%I

%S 7,10,11,12,13,14,15,17,18,20,21,22,23,25,27,28,30,31,32,33,35,37,38,

%T 39,40,42,43,45,46,47,48,49,50,52,53,55,57,58,59,60,62,63,65,66,67,68,

%U 70,71,72,73,74,75,76,77,78,80,81,82,83,84,85,86,87,88,90,91,92,93,94,95,97,98,99,100,101,102,103,104,105,107,108,109,110,111,112,113

%N Anti-abundant numbers.

%C An anti-abundant number is a number n for which sigma*(n) > n, where sigma*(n) is the sum of the anti-divisors of n. Like A005101 but using anti-divisors.

%H Paolo P. Lava, <a href="/A192268/b192268.txt">Table of n, a(n) for n = 1..5000</a>

%F A000027 = A073930 UNION A192267 UNION {this set}.

%e 25 is anti-abundant because its anti-divisors are 2, 3, 7, 10, 17 and their sum is 39 > 25.

%p isA192268 := proc(n) A066417(n) > n ; end proc:

%p for n from 1 to 500 do if isA192268(n) then printf("%d,",n); end if; end do: # _R. J. Mathar_, Jul 04 2011

%Y Cf. A066417, A005101, A066272, A192267.

%K nonn,easy

%O 1,1

%A _Paolo P. Lava_, Jun 28 2011

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Last modified August 6 12:33 EDT 2020. Contains 336246 sequences. (Running on oeis4.)