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%I #28 Feb 10 2024 11:35:35
%S 14,16,46,446,1146,26766,35805,143605,179086,185946,437745,1187725,
%T 1194646,1327086,1746946,2201806,2893605,3003385,3574725,3730125,
%U 4053586,4928385,5715325,6220305,7507946,9423645,9897186
%N Numbers k such that sigma(k) = sigma(k+9).
%H Donovan Johnson, <a href="/A015877/b015877.txt">Table of n, a(n) for n = 1..200</a>
%t Select[Range[10000000], DivisorSigma[1, #]==DivisorSigma[1, # + 9] &] (* _Vincenzo Librandi_, Mar 10 2014 *)
%t Position[Partition[DivisorSigma[1,Range[10^7]],10,1],_?(#[[1]] == #[[10]]&),{1},Heads->False]//Flatten (* _Harvey P. Dale_, Aug 25 2016 *)
%o (PARI) is(n)=sigma(n)==sigma(n+9) \\ _Charles R Greathouse IV_, Mar 09 2014
%Y Cf. A002961, A007373, A015861, A015863, A015865, A015866, A015867, A015876, A015880, A015881, A015882, A015883, A181647.
%K nonn
%O 1,1
%A _Robert G. Wilson v_
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