This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A065868 #23 Dec 15 2017 17:35:45 %S A065868 2,14,887,4267,5163,8867,18644,24429,130911 %N A065868 Initial n digits in decimal portion of golden ratio phi (or tau) = (1 + sqrt 5)/2 form a prime number. %C A065868 887 certified prime with Primo. %C A065868 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 %C A065868 Search limit is 200000. - _Serge Batalov_, Jun 21 2017 %t A065868 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 *) %Y A065868 Cf. A047658, A057563, A001622. %K A065868 base,nonn %O A065868 1,1 %A A065868 _Jason Earls_, Dec 07 2001 %E A065868 a(4)-a(6) from _Ryan Propper_, Aug 12 2005 %E A065868 a(7)-a(9) from _Serge Batalov_, Jun 21 2017