%I A071116
%S A071116 2049,81,383,67,7,25,11,103,17,271,29,159,1416741,35
%N A071116 Least m such that sigma(n + phi(m)) = sigma(phi(m)).
%C A071116 a(15), if it exists, is at least 10^8. The sequence then continues 31, 
               239, 41, 227, 43, 25, 339, 683, 71, 31, 151, 43, 67, 2897, 89, 59, 
               61, 81, 97, 35, 131, 110039, 461, 69, 103, 31, 123, 87981, 1941, 
               53, 197, 311, 213, 41, 161, 141, 187, 67, 143, 167, 161, 89, 353, 
               479, 339, 124809, 339, 61, 143, 79, 233, 6723723, 313, 724747, 97, 
               113, 211, 863, 281, 131, 343, 121, 569, 59217, 127, 127, 309, 61, 
               271, 103, 1329, 359, 229, 79, 299, 89, 911, 264263, 575, 14627, 281, 
               139, 203, 267, 211, ..., . [From Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Jun 09 2009]
%t A071116 a[n_] := For[m=1, True, m++, p=EulerPhi[m]; If[DivisorSigma[1, n+p]==DivisorSigma[1, 
               p], Return[m]]]
%t A071116 f[n_] := Block[{k = 1}, While[ DivisorSigma[1, n + EulerPhi@k] != DivisorSigma[1, 
               EulerPhi@k], k++ ]; k] [From Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Jun 09 2009]
%Y A071116 Cf. A000010, A000203.
%Y A071116 Sequence in context: A017303 A017423 A017555 this_sequence A060949 A017685 
               A013959
%Y A071116 Adjacent sequences: A071113 A071114 A071115 this_sequence A071117 A071118 
               A071119
%K A071116 nonn
%O A071116 1,1
%A A071116 Jason Earls (zevi_35711(AT)yahoo.com), May 27 2002
%E A071116 Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com), Jun 02 2002
%E A071116 I extended the search from 7*10^7 to 10^8 Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Jun 09 2009