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 A018830 #15 Apr 05 2024 08:19:57 %S A018830 0,1,3,4,6,9,18,24,28,36,54,81,108,136,144,168,216,324,486,648,816, %T A018830 864,1008,1216,1296,1944,2916,3888,4896,5184,6048,6458,6561,7296,7776, %U A018830 8451,11664,16768,17496,22779,23328,23985,29376,29889,31104,34299,34549,36288 %N A018830 Numbers n such that n is a substring of its square in base 6 (written in base 10). %t A018830 Select[Range[0, 10^5], StringContainsQ[IntegerString[#^2, 6], IntegerString[#, 6]] &] (* _Paolo Xausa_, Apr 05 2024 *) %Y A018830 Cf. A018826 (base 2), A018827 (base 3), A018828 (base 4), A018829 (base 5), A018831 (base 7), A018832 (base 8), A018833 (base 9), A018834 (base 10). %K A018830 nonn,base %O A018830 1,3 %A A018830 _David W. Wilson_