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 A078830 #5 Mar 30 2012 18:50:29 %S A078830 2,3,4,8,9,16,32,33,64,65,128,129,256,512,513,1024,1025,2048,2049, %T A078830 4096,4097,8192,8193,16384,16385,32768,32769,65536,131072,131073, %U A078830 262144,262145,524288,524289,1048576,1048577,2097152,2097153,4194304,4194305 %N A078830 Numbers having in binary representation exactly one binary substring representing a prime. %C A078830 A078827(a(n)) = 1; subsequence of A078829 and of A078831; %C A078830 for k>2 also floor(a(k)/2) belongs to the sequence. %e A078830 p=2 -> '10' is the only prime contained exactly once in 2^k, k>0. %Y A078830 Cf. A078827, A078829, A007088, A000079, A048578. %K A078830 nonn,base %O A078830 1,1 %A A078830 _Reinhard Zumkeller_, Dec 08 2002 %E A078830 Extended by _Ray Chandler_, Nov 03 2008