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A337364
Numbers b such that b^(2^i) + 1 is prime for i = 0...7.
4
1, 240164550712338756, 3686834112771042790, 6470860179642426900, 7529068955648085700, 10300630358100537120, 16776829808789151280, 17622040391833711780, 19344979062504927000, 23949099004395080026, 25348938242408650240, 30262840543567048476, 35628481193915651646
OFFSET
1,2
COMMENTS
Explicitly, for each b, the eight numbers b+1, b^2+1, b^4+1, b^8+1, b^16+1, b^32+1, b^64+1, and b^128+1 must be primes (generalized Fermat primes).
LINKS
Jeppe Stig Nielsen, Table of n, a(n) for n = 1..31 (found by Rob Gahan)
Yves Gallot, GFP (Generalized Fermat Progressions) / gfp8, software for calculating this sequence.
KEYWORD
nonn
AUTHOR
Jeppe Stig Nielsen, Aug 25 2020
EXTENSIONS
a(10)-a(12) from Jeppe Stig Nielsen, Sep 04 2020
a(13) found by Rob Gahan added by Jeppe Stig Nielsen, Feb 15 2021
STATUS
approved