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1,2
17 divides a(n) for n>1. a(n) = 17^(n-1) for n<7. a(7) = 20231*17^2.
Table of n, a(n) for n=1..21.
Cf. A001026 = Powers of 17. Cf. A015969 = numbers n such that n | 16^n + 1.
Sequence in context: A045607 A045606 A171291 * A015969 A001026 A178765
Adjacent sequences: A128355 A128356 A128357 * A128359 A128360 A128361
hard,nonn
Alexander Adamchuk, Mar 01 2007
a(8)-a(10) from Farideh Firoozbakht, Mar 05 2007
More terms from Ryan Propper, Dec 31 2007
a(20)-a(24) from Alexander Adamchuk, May 17 2010
approved