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 A135053 #3 Mar 31 2012 13:22:05 %S A135053 2,21,23,80,96,111,168,230,281,347,558,704 %N A135053 Greatest integer M(i)=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 A135053 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 A135053 A(2)=1,A(1)=2 so A(2)=A(1)/2 so M(1)=1 %e A135053 A(5)=1,A(4)=2 but A(5)=A(2) .......... %e A135053 A(21)=7,A(20)=14 A(21)=A(20)/2 and A(21)>A(2) so M(2)=21 %Y A135053 Cf. A087425, A135054. %K A135053 nonn,uned %O A135053 1,1 %A A135053 _Pierre CAMI_, Nov 15 2007