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A134304 Least k such that k*2^n*(k*2^n-1)-1 and k*2^n*(k*2^n-1)+1 are twin primes. 2
2, 1, 2, 1, 11, 21, 57, 211, 141, 156, 78, 39, 140, 70, 35, 214, 107, 90, 45, 309, 330, 165, 120, 60, 30, 15, 435, 651, 420, 210, 105, 429, 1143, 576, 288, 144, 72, 36, 18, 9, 116, 58, 29, 2286, 1143, 1638, 819, 1071, 983, 1983 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
PROG
(PARI) a(n) = {my(k=1); while (!(isprime(p=k*2^n*(k*2^n-1)-1) && isprime(p+2)), k++); k; } \\ Michel Marcus, Sep 17 2019
CROSSREFS
Sequence in context: A097749 A126906 A179508 * A211096 A134569 A295853
KEYWORD
nonn
AUTHOR
Pierre CAMI, Oct 19 2007
STATUS
approved

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Last modified June 15 13:08 EDT 2024. Contains 373407 sequences. (Running on oeis4.)