Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #9 Sep 16 2017 00:30:48
%S 61,61803398874989
%N Primes formed by the initial digits of the decimal expansion of 1/(Golden Ratio).
%C The next term consists of the first 887 digits of 1/(Golden Ratio) and is too large to show here.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Phi-Prime.html">Phi-Prime</a>
%p Digits := 1000: n0 := evalf((sqrt(5)-1)/2): for i from 1 to 10000 do t1 := trunc(10^i*n0): if isprime(t1) then print(t1): fi: od:
%t With[{gr=RealDigits[1/GoldenRatio,10,1000][[1]]}, Select[Table[ FromDigits[ Take[ gr,n]], {n,1000}], PrimeQ]] (* _Harvey P. Dale_, Oct 17 2012 *)
%K nonn,base,bref
%O 1,1
%A _Michel Lagneau_, Feb 17 2010