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A128683
Numbers k such that k^3 divides 10^(k^2) + 1.
21
1, 11, 253, 11891, 35167, 45023, 47927, 96569, 276859, 640343, 1035529, 1102321, 1652849, 2221087, 6367757, 16339367, 19588019, 26499979, 30096121, 48669863, 51809087, 74901409, 88023001, 89007677, 104391089, 105080767, 143938531
OFFSET
1,2
COMMENTS
11 divides a(n) for n > 1.
LINKS
MATHEMATICA
Select[Range[5*10^6], Mod[ 10^(#^2)+1, #^3]==0 &] (* G. C. Greubel, Jan 18 2018 *)
KEYWORD
hard,nonn
AUTHOR
Alexander Adamchuk, Mar 31 2007
EXTENSIONS
More terms from J. Mulder (jasper.mulder(AT)planet.nl), Jan 26 2010
Terms a(16) onward from Max Alekseyev and Alexander Adamchuk, May 12 2010
STATUS
approved