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A095967 Numbers n such that r3(k) * 2^n + 1 is prime, where r3() = A002277 and k is the number of decimal digits of 2^n. 0
1, 2, 6, 9, 20, 46, 58, 64, 69, 110, 158, 178, 186, 268, 424, 624, 641, 1236, 1593, 2264, 2870, 5797, 7518, 7688, 9300 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(1) through a(25) have been proved to be prime with WinPFGW. a(25) has 5600 digits. No more terms up to 12800.
Results were computed using the PrimeFormGW (PFGW) primality-testing program. - Hugo Pfoertner, Nov 14 2019
LINKS
EXAMPLE
a(4)=9 because 333 * 2^9 + 1 = 170497, a prime.
CROSSREFS
Sequence in context: A265016 A279897 A336131 * A316429 A337639 A047161
KEYWORD
more,nonn,base
AUTHOR
Jason Earls, Jul 15 2004
STATUS
approved

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Last modified June 12 23:30 EDT 2024. Contains 373362 sequences. (Running on oeis4.)