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A134305 Numbers k such that A134303(k) is the lesser of twin primes, A134303(k) = A134304(k). 2
1, 2, 3, 4, 40, 59, 60, 61, 62, 241, 276, 404, 2159, 2160, 2161 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..15.

PROG

(PARI) a3(n) = {my(k=1); while (!(isprime(k*2^n*(k*2^n-1)-1)), k++); k; }

a4(n) = {my(k=1); while (!(isprime(p=k*2^n*(k*2^n-1)-1) && isprime(p+2)), k++); k; }

isok(n) = a3(n) == a4(n); \\ Michel Marcus, Sep 17 2019

CROSSREFS

Cf. A134303, A134304.

Sequence in context: A302943 A037326 A024634 * A000033 A270350 A060411

Adjacent sequences:  A134302 A134303 A134304 * A134306 A134307 A134308

KEYWORD

nonn,more

AUTHOR

Pierre CAMI, Oct 19 2007

EXTENSIONS

a(12)-a(15) from Jinyuan Wang, Mar 05 2020

STATUS

approved

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Last modified June 23 05:08 EDT 2021. Contains 345395 sequences. (Running on oeis4.)