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 A188499 #20 Dec 10 2018 08:53:12 %S A188499 1,2,5,7,23,239 %N A188499 Intersection of A089633 and A188341. %C A188499 Binomial coefficient predictors in both bases 2 and 3 (for definition, see paper in link). %C A188499 Next term is > 5*10^300, if it exists. %H A188499 V. Shevelev, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL14/Shevelev/shevelev14.html">Binomial Coefficient Predictors</a>, Journal of Integer Sequences, Vol. 14 (2011), Article 11.2.8. %t A188499 aQ[n_]:= DigitCount[n, 2, 0] < 2 && DigitCount[n, 3, 0] == 0 && DigitCount[n, 3, 1] < 2; Select[Range[1000], aQ] (* _Amiram Eldar_, Dec 10 2018 *) %o A188499 (PARI) isok2(n) = my(b=binary(n)); #select(x->(x==0), b) <= 1; \\ A089633 %o A188499 isok3(n) = my(d=digits(n, 3)); (#select(x->(x==0), d) == 0) && (#select(x->(x==1), d) <= 1); \\ A188341 %o A188499 isok(n) = isok2(n) && isok3(n); \\ _Michel Marcus_, Dec 10 2018 %Y A188499 Cf. A089633, A188341. %K A188499 nonn,base,more %O A188499 0,2 %A A188499 _Vladimir Shevelev_, Apr 02 2011