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a(n) is smallest number such that a(n)^2 + 1 is divisible by 41^n.
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%I #4 Nov 05 2012 12:19:09

%S 0,9,378,11389,1251967,46464143,2363588163,92615568742,287369842623,

%T 112076323050317,2403749863808044,56094387104417648,

%U 1156752450536914530,43970228150195457632,10132163897314954464899,503212117431217218892992,19164391897329672149556204

%N a(n) is smallest number such that a(n)^2 + 1 is divisible by 41^n.

%e a(3) = 11389 because 11389^2+1 = 2 * 41 ^ 3 * 941.

%t b=9;n41=41;jo=Join[{0,b},Table[n41=41*n41;b=PowerMod[b,41,n41];b=Min[b,n41-b],{99}]]

%Y Cf. A002522, A049532, A034939, A218709, A218710, A218712, A218713.

%K nonn

%O 0,2

%A _Michel Lagneau_, Nov 04 2012