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 A268479 #5 Feb 15 2016 17:08:06 %S A268479 0,0,1,2,0,1,1,1,2,1,3,1,1,2 %N A268479 For p = prime(n), number of primes (including p) in the trajectory of p under the procedure in A244550, also allowing the Wieferich prime 2, that are not terms of a repeating cycle. %C A268479 a(15) is unknown, since there is no known Wieferich prime to base 47 (cf. Fischer link). %H A268479 R. Fischer, <a href="http://www.fermatquotient.com/FermatQuotienten/FermQ_Sort.txt">Thema: Fermatquotient B^(P-1) == 1 (mod P^2)</a> %e A268479 The trajectory of 31 starts 31, 7, 5, 2, 1093, 2, 1093, 2, 1093, ...., entering a repeating cycle consisting of the terms 2 and 1093. There are three terms before the cycle, so a(11) = 3. %Y A268479 Cf. A244550, A252801, A252802, A252812. %K A268479 nonn,hard,more %O A268479 1,4 %A A268479 _Felix Fröhlich_, Feb 05 2016