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 A280746 #9 Feb 10 2017 14:03:59 %S A280746 1,2,3,6,13,30,65,127,258,530,1009,1988,3942,8004,16195,32389,64923, %T A280746 129870,260326,520787,1043257,2085202,4171403,8338443 %N A280746 Index of 2^n in A280864. %e A280746 A280864(30) = 32, so a(5) = 30. %Y A280746 Cf. A280864, A282024. %K A280746 nonn,more %O A280746 0,2 %A A280746 _N. J. A. Sloane_, Jan 13 2017 %E A280746 a(17)-a(23) from _Lars Blomberg_, Jan 14 2017