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 A138834 #7 Mar 14 2020 06:52:38 %S A138834 2,16,4096,262144,1152921504606846976,81129638414606681695789005144064 %N A138834 Bisection of even superperfect numbers A061652. %C A138834 Also, bisection of superperfect numbers A019279, if there are no odd superperfect numbers. %H A138834 Jinyuan Wang, <a href="/A138834/b138834.txt">Table of n, a(n) for n = 1..9</a> %F A138834 a(n) = A061652(2*n-1). - _Jinyuan Wang_, Mar 14 2020 %Y A138834 Cf. A019279, A061652, A099057, A099058, A134721, A134722. %K A138834 nonn %O A138834 1,1 %A A138834 _Omar E. Pol_, Apr 06 2008