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 A334053 Least b such that b^(2^n) + 1 is a Proth prime (A080076). 1
 2, 2, 2, 2, 2, 96, 6912, 960, 16256, 2013184, 235520, 61184, 125440, 992256, 155615232, 550207488, 12192710656 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Every term b is in A116882 (the prime factor 2 of b must account for more than the square root of b). For n up to about 11, a(n) can be found with the PARI function below. From there up to n=14, you can find a(n) by filtering lists of known primes of the form b^(2^n) + 1. LINKS Table of n, a(n) for n=0..16. Chris K. Caldwell, The Prime Pages, 12192710656^65536 + 1 PROG (PARI) a(n) = forstep(b=2, +oo, 2, 2*valuation(b, 2)>logint(b, 2)&&ispseudoprime(b^(2^n)+1)&&return(b)) CROSSREFS Cf. A056993, A080076, A116882. Sequence in context: A056993 A338931 A057331 * A270374 A067089 A339027 Adjacent sequences: A334050 A334051 A334052 * A334054 A334055 A334056 KEYWORD more,nonn AUTHOR Jeppe Stig Nielsen, Sep 07 2020 EXTENSIONS a(15) calculated by Pavel Atnashev added by Jeppe Stig Nielsen, Sep 18 2020 a(16) calculated by Pavel Atnashev added by Jeppe Stig Nielsen, Jan 05 2021 STATUS approved

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Last modified March 1 08:00 EST 2024. Contains 370430 sequences. (Running on oeis4.)