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 A065868 Initial n digits in decimal portion of golden ratio phi (or tau) = (1 + sqrt 5)/2 form a prime number. 0
 2, 14, 887, 4267, 5163, 8867, 18644, 24429, 130911 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 887 certified prime with Primo. Note: the upper bound of 10^6 in this program has not actually been reached, so the next term may occur at any value >8867. - Ryan Propper, Aug 12 2005 Search limit is 200000. - Serge Batalov, Jun 21 2017 LINKS MATHEMATICA phi = First@ RealDigits[N[GoldenRatio - 1, 10^6 + 1]]; Do[k = FromDigits[Take[phi, n]]; If[PrimeQ[k], Print[n]], {n, 1, 10^6}] (* Ryan Propper, Aug 12 2005, edited by Michael De Vlieger, Jun 21 2017 *) CROSSREFS Cf. A047658, A057563, A001622. Sequence in context: A211891 A060599 A319774 * A144017 A032419 A225163 Adjacent sequences:  A065865 A065866 A065867 * A065869 A065870 A065871 KEYWORD base,nonn AUTHOR Jason Earls, Dec 07 2001 EXTENSIONS a(4)-a(6) from Ryan Propper, Aug 12 2005 a(7)-a(9) from Serge Batalov, Jun 21 2017 STATUS approved

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Last modified September 21 16:31 EDT 2021. Contains 347598 sequences. (Running on oeis4.)