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 A135054 #3 Mar 31 2012 13:22:05 %S A135054 1,7,13,15,17,75,102,173,181,229,513,539 %N A135054 Greatest integer K(i)=A085427(n) such that A085427(n)=A085427(n-1)/2 and K(i+1)>K(i) with A085427(n)=least k such that k*2^n-1 is prime ( Mersenne prime when k=1). %e A135054 A085427 =3,2,1,1,2,1,2,1,5,7,5,3,2,1,5,4,2,1,2,1,14,7,26,13,39,22 %e A135054 A(2)=1,A(1)=2 so A(2)=A(1)/2 so K(1)=1 %e A135054 A(5)=1,A(4)=2 but A(5)=A(2) .......... %e A135054 A(21)=7,A(20)=14 A(21)=A(20)/2 and A(21)>A(2) so K(2)=7 %Y A135054 Cf. A087425, A135053. %K A135054 nonn,uned %O A135054 1,2 %A A135054 _Pierre CAMI_, Nov 15 2007