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A218714
a(n) is smallest number such that a(n)^2 + 1 is divisible by 41^n.
6
0, 9, 378, 11389, 1251967, 46464143, 2363588163, 92615568742, 287369842623, 112076323050317, 2403749863808044, 56094387104417648, 1156752450536914530, 43970228150195457632, 10132163897314954464899, 503212117431217218892992, 19164391897329672149556204
OFFSET
0,2
EXAMPLE
a(3) = 11389 because 11389^2+1 = 2 * 41 ^ 3 * 941.
MATHEMATICA
b=9; n41=41; jo=Join[{0, b}, Table[n41=41*n41; b=PowerMod[b, 41, n41]; b=Min[b, n41-b], {99}]]
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 04 2012
STATUS
approved