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 A091679 #5 Jul 11 2015 00:52:11 %S A091679 1,3,7,8,9,11,12,13,14,16,18,19,21,22,23,24,26,27,28,29,31,32,35,36, %T A091679 37,38,39,40,43,44,45,46,47,48,49,52,53,54,55,56,57,60,61,62,63,64,66, %U A091679 69,70,71,72,73,74,77,78,79,80,81,82,83,86,87,88,89,90,91,94,95,96,97,98 %N A091679 In base 4, numbers n not of the form k + reverse(k) for any k. %C A091679 Base-4 analog of A067031. Complement of A091678. %e A091679 31 is a term since 31 (decimal) = 133 and there is no k such that k + reverse(k) = 133 in base 4. %Y A091679 Cf. A091678, A067031. %K A091679 base,easy,nonn %O A091679 0,2 %A A091679 _Klaus Brockhaus_, Jan 28 2004