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%I #11 Sep 20 2018 08:16:29
%S 1,10,373,5,4,372,5,26,248,2,13,186,11,562,247,13,627,124,195,1,183,
%T 86,245,93,5184,8,185,281,1623,4320,72,738,43,2296,1,62,20,2312,95,
%U 3240,576,732,33,43,111,4600,540100,492,115,2592,209,4,25383,2388,629,549,65,1732,64476,2160,20,36,61
%N a(n) is the smallest k such that uphi(k*n) = uphi(k*n+1), or 0 if no such k exists.
%e a(3) = 373 because uphi(373*3) = uphi(373*3+1) and 373 is the smallest number with this property.
%o (PARI) uphi(n) = my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[1, 2]-1);
%o a(n) = {my(k = 1); while (uphi(k*n) != uphi(k*n+1), k++); k; }
%Y Cf. A047994, A275412, A287055.
%K nonn
%O 1,2
%A _Altug Alkan_, Aug 25 2017
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