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 A043311 #6 Feb 03 2014 12:46:14 %S A043311 1,2,3,4,5,6,49,51,52,53,54,55,98,99,101,102,103,104,147,148,149,151, %T A043311 152,153,196,197,198,199,201,202,245,246,247,248,249,251,294,295,296, %U A043311 297,298,299,2402,2403,2404,2405,2406,2407,2499 %N A043311 a(n)=A033005(n)/8. %C A043311 Numbers which, written in base 49, have only digits 0 through 6 and no two adjacent digits equal. - _M. F. Hasler_, Feb 03 2014 %o A043311 (PARI) is_A043311(n)=(n=[n])&&!until(!n[1],((n=divrem(n[1],49))[2]<7 && n[1]%7!=n[2])||return) \\ _M. F. Hasler_, Feb 03 2014 %Y A043311 Cf. A043307 - A043320, A043291, A033001 - A033014, A033016 - A033029. ~ %K A043311 nonn,base %O A043311 1,2 %A A043311 _Clark Kimberling_