A213239 Numbers n such that sum of digits of n = sum of digits of anti-divisors of n.
5, 8, 64, 691, 1779, 2851, 6361, 9066, 9606, 9771, 10789, 10996, 18996, 21481, 22569, 27529, 27691, 31516, 36709, 36776, 42649, 48651, 53296, 56586, 58749, 60369, 64794, 72889, 76754, 78766, 79374, 79896, 80989, 86596, 90606, 90879, 92766, 96171, 98979, 108529
Offset: 1
Examples
Sum of digits of 1779 is 1+7+7+9=24. Anti-divisors of 1779 are 2, 6, 1186 and their digits’ sum is 2+6+1+1+8+6=24.
Programs
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Maple
with(numtheory); A213239:=proc(q) local a,b,c,d,k,n; for n from 1 to q do a:=0; b:=0; for k from 2 to n-1 do if abs((n mod k)-k/2)<1 then c:=k; while c>0 do b:=b+(c mod 10); c:=trunc(c/10); od; fi; od; c:=n; d:=0; while c>0 do d:=d+(c mod 10); c:=trunc(c/10); od; if b=d then print(n); fi; od; end: A213239(100000);
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Python
[n for n in range(1,10**5) if sum([sum([int(x) for x in str(d)]) for d in range(2,n) if n % d and 2*n % d in [d-1,0,1]]) == sum([int(x) for x in str(n)])] # Chai Wah Wu, Aug 08 2014