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A218715
a(n) is smallest number such that a(n)^2 + 1 is divisible by 53^n.
5
0, 23, 500, 27590, 623098, 23048345, 5041394261, 416081467190, 11331029931180, 50928660480181, 6548598523124085, 2441875986594058601, 76594163421571591377, 7783548304686046882879, 252583670951378815076851, 4392422457122810120236558, 1165802007767335105471573954
OFFSET
0,2
EXAMPLE
a(3) = 27590 because 27590^2+1 = 53 ^ 3 * 5113.
MATHEMATICA
b=23; n53=53; jo=Join[{0, b}, Table[n53=53*n53; b=PowerMod[b, 53, n53]; b=Min[b, n53-b], {99}]]
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 04 2012
STATUS
approved