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 A135651 #3 Mar 30 2012 17:33:53 %S A135651 10,100,10000,1000000,1000000000000,10000000000000000, %T A135651 1000000000000000000,1000000000000000000000000000000 %N A135651 Even superperfect numbers written in base 2. %C A135651 Also, superperfect numbers (A019279) written in base 2 (If there are no odd perfect numbers). %C A135651 Also, concatenation of "1" and A090748(n) digits "0". %C A135651 The number of digits of a(n) is equal to A000043(n) and also equal to the number of digits of n-th Mersenne prime written in base 2 (see A117293, A135650). %e A135651 a(3)=10000 because the 3rd even superperfect number A061652(3)=16 and 16 written in base 2 is equal to 10000. %Y A135651 Cf. A000043, A000668, A019279, A061652, A090748, A117293, A135650. %K A135651 base,nonn %O A135651 1,1 %A A135651 _Omar E. Pol_, Feb 23 2008