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A045588
Numbers k that divide 9^k + 3^k.
1
1, 2, 3, 6, 9, 10, 18, 21, 27, 30, 50, 54, 63, 81, 90, 147, 150, 162, 171, 189, 243, 250, 270, 333, 438, 441, 450, 486, 513, 567, 729, 750, 810, 903, 999, 1029, 1197, 1250, 1314, 1323, 1350, 1458, 1539, 1701, 2187, 2190, 2250, 2331, 2430, 2709, 2997, 3087
OFFSET
1,2
LINKS
MATHEMATICA
Select[Range[3100], Divisible[9^#+3^#, #]&] (* Harvey P. Dale, Aug 13 2015 *)
Select[Range[300], Divisible[PowerMod[9, #, #] + PowerMod[3, #, #], #] &] (* Amiram Eldar, Oct 23 2021 *)
CROSSREFS
Cf. A074610.
Sequence in context: A214974 A286434 A288930 * A191178 A191127 A015898
KEYWORD
nonn
STATUS
approved