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%I #11 Feb 10 2021 01:11:47
%S 7,13,14,20,30,45,76,630,688,2310,8896,133888,537051136,1631268870
%N Numbers k such that sigma(k) == 0 (mod k-6).
%e sigma(7) mod (7-6) = 8 mod 1 = 0.
%p with(numtheory); P:=proc(q,h) local n; for n from 1 to q do
%p if n+h>0 then if type(sigma(n)/(n+h),integer) then print(n); fi; fi; od; end: P(10^9,-6);
%t Select[Range[7, 10^6], Mod[DivisorSigma[1, #], # - 6] == 0 &] (* _Michael De Vlieger_, Jul 05 2016 *)
%Y Cf. A000203, A045770, A067702, A088833, A181598, A274551-A274557, A274559-A274566.
%K nonn,more
%O 1,1
%A _Paolo P. Lava_, Jul 05 2016
%E a(13)-a(14) from _Giovanni Resta_
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