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A218716
a(n) is smallest number such that a(n)^2 + 1 is divisible by 61^n.
4
0, 11, 682, 51412, 6304056, 144762466, 9435321777, 988322434636, 71294762793847, 3138611770750343, 283798117998769727, 15409745938584647495, 320007169218635518122, 45443939732277600209579, 207359227164430355867160, 59053635973003478214807486
OFFSET
0,2
EXAMPLE
a(3) = 51412 because 51412^2+1 = 5 * 17 * 61 ^ 3 * 137.
MATHEMATICA
b=11; n61=61; jo=Join[{0, b}, Table[n61=61*n61; b=PowerMod[b, 61, n61]; b=Min[b, n61-b], {99}]]
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 04 2012
STATUS
approved