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 A057894 #2 Mar 30 2012 17:38:10 %S A057894 2,5,6,7,9,13,15,17,23,27,29,31,33,39,43,47,51,53,55,57,61,71,77,79, %T A057894 83,87,89,91,99,101,107,109,115,117,121,127,129,139,141,147,149,151, %U A057894 167,169,173,181,185,191,197,199,201,203,205,209,213,223,227,233,239,241 %N A057894 Negabinary numbral "primes". %C A057894 "Primes" have no other distinct divisors, up to multiplication by units. (Units are [1]=1 and [3]=-1.) %e A057894 [2]=-2, [5]=5, [6]=2, [7]=3, [9]=-7, [13]=-3, etc %Y A057894 A005351, A005352, A057892, A057893. %K A057894 easy,nonn %O A057894 0,1 %A A057894 _Marc LeBrun_, Sep 25 2000