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%I #42 Oct 23 2019 06:56:16
%S 3,4,9,19,24,131,139,339,5881,14849,29501,57169,63061,65789,542781,
%T 2439241,3197249,4111561,8614481,48657789,218234169,309296261,
%U 731499089,1191549689,1569571661,2471800109,5687426561,9505043161,67784277581,79468538969,257067141569,290324629889,397393221689,445568135041,2260763053809
%N Almost anti-perfect numbers.
%C An almost anti-perfect number is a least anti-deficient number, i.e., one such that sigma*(n)=n-1, where sigma*(n) is the sum of the anti-divisors of n. Like almost perfect numbers (see link) but using anti-divisors.
%C a(29) > 2*10^10. - _Donovan Johnson_, Sep 22 2011
%H Jud McCranie, <a href="/A192288/b192288.txt">Table of n, a(n) for n = 1..36</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AlmostPerfectNumber.html">Almost perfect number</a>
%e Anti-divisors of 5881 are 2, 3, 9, 19, 619, 1307, 3921. Their sum is 5880 and 5880=5881-1.
%p P:=proc(n)
%p local a,i,k;
%p for i from 3 to n do
%p a:=0;
%p for k from 2 to i-1 do
%p if abs((i mod k)-k/2)<1 then a:=a+k; fi;
%p od;
%p if i-1=a then print(i); fi;
%p od;
%p end:
%p P(1000000);
%Y Cf. A066272, A073930, A192267, A192287.
%K nonn
%O 1,1
%A _Paolo P. Lava_, Aug 02 2011
%E a(15)-a(28) from _Donovan Johnson_, Sep 22 2011
%E a(29)-a(34) from _Jud McCranie_, Aug 31 2019
%E a(35) from _Jud McCranie_, Sep 05 2019
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