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 A080348 #13 Oct 27 2015 03:27:43
%S A080348 2,2,2,5,2,5,3,7,11,5,11,7,23,13,11,3,5,2,7,5,3,7,5,13,43,43,29,17,5,
%T A080348 2,19,11,5,3,7,5,5,3,7,7,11,3,3,7,11,2,13,7,19,13,11,11,5,3,3,3,7,7,
%U A080348 11,3,3,7,13,37,17,7,3,7,5,5,5,2,11,5,5,5,5,2,5,5,37,7,157,53,1361,131,107
%N A080348 Costé prime expansion of Catalan's constant.
%C A080348 For x in (0,1], define P(x) = min{p: p prime, 1/x < p}, Phi(x) = P(x)x - 1. Costé prime expansion of x(0) is sequence a(0), a(1), ... given by x(n) = Phi(x(n-1)) (n>0), a(n) = P(x(n)) (n >= 0).
%H A080348 A. Costé, <a href="http://www.emis.de/journals/EM/expmath/volumes/11/11.3/Coste383_405.pdf">Sur un système fibré lié à la suite des nombres premiers</a>, Exper. Math., 11 (2002), 383-405.
%p A080348 Digits := 500: P := proc(x) local y; y := ceil(evalf(1/x)); if isprime(y) then y else nextprime(y); fi; end; F := proc(x) local y,i,t1; y := x; t1 := []; for i from 1 to 100 do p := P(y); t1 := [op(t1),p]; y := p*y-1; od; t1; end; F(Catalan);
%Y A080348 Cf. A079385, A079386, A079366, A079367, A079368.
%K A080348 nonn,easy
%O A080348 0,1
%A A080348 Mark Hudson (mrmarkhudson(AT)hotmail.com), Feb 17 2003