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 A086386 #17 Feb 22 2018 10:55:38
%S A086386 5,19,71,3691,191861,26947261171
%N A086386 Numerators of the rational convergents to sqrt(3) if both numerators and denominators are primes.
%C A086386 These numbers are rare.
%o A086386 (PARI) cfracnum(m,f) = { cfr = vector(10000); x=f; for(n=0,m, i=floor(x); x=1/(x-i); cfr[n+1] = i; ); for(m1=0,m, r=cfr[m1+1]; forstep(n=m1,1,-1, r = 1/r; r+=cfr[n]; ); numer=numerator(r); denom=denominator(r); if(isprime(numer) & isprime(denom),print1(numer",")); ) }
%Y A086386 Cf. A001834.
%K A086386 nonn,frac,more
%O A086386 1,1
%A A086386 _Cino Hilliard_, Sep 06 2003