A277114 - OEIS

%I #10 Oct 04 2016 13:31:43

%S 504,1350,3267,3834,6291,6597,7920,12024,13680,19800,19872,19980,

%T 25047,26604,30645,46251,49491,53091,54000,55647,57951,60309,60741,

%U 62019,62991,64530,65997,70020,72522,80982,86940,86994,95580,99990,100908,103374,103950,117702

%N Numbers such that the decimal digits of sigma(n) are a permutation of those of sigma(n)-n.

%H Paolo P. Lava, <a href="/A277114/b277114.txt">Table of n, a(n) for n = 1..100</a>

%e sigma(504) = 1560 and sigma(504) - 504 = 1056. - Typo fixed by _Ivan N. Ianakiev_, Oct 04 2016

%p with(numtheory): P:= proc(q) local n; for n from 1 to q do

%p if sort(convert(sigma(n),base,10))=sort(convert(sigma(n)-n,base,10)) then print(n); fi; od; end: P(10^9);

%t Select[Range[10^5],Sort[IntegerDigits[DivisorSigma[1,#]]]==Sort[IntegerDigits[DivisorSigma[1,#]-#]]&] (* _Ivan N. Ianakiev_, Oct 04 2016 *)

%Y Cf. A000203, A001065, A115920,

%K nonn,base,easy

%O 1,1

%A _Paolo P. Lava_, Sep 30 2016