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 A229626 #19 Jan 06 2023 22:27:03
%S A229626 2,2,3,6,6,11256895,15682744,45779314036,687860415949
%N A229626 a(n) is the smallest m such that 2*m^k-1 is prime for k = 1, 2, ..., n.
%t A229626 a[1]=2;a[n_]:=a[n]=(For[m=a[n-1],Union[Table[PrimeQ[2 m^k-1],{k,n}]]!={True},m++];m)
%o A229626 (PARI) a(n)=my(m=2); while(1,for(k=1, n, if(!ispseudoprime(2*m^k-1), m++; next(2))); return(m)) \\ _Charles R Greathouse IV_, Oct 01 2013
%Y A229626 Cf. A229627.
%K A229626 nonn,more
%O A229626 1,1
%A A229626 _Farideh Firoozbakht_, Sep 27 2013
%E A229626 a(8) from _Giovanni Resta_, Oct 01 2013
%E A229626 a(9) from _Tyler Busby_, Jan 06 2023