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 A204691 #13 Oct 30 2018 10:31:02 %S A204691 10278,12543,12586,13268,13278,13698,14098,15963,16549,16854,17529, %T A204691 18072,19023,20316,20513,20754,21397,21439,23019,23178,24807,25941, %U A204691 26351,26409,27105,27984,28346,28731,29034,29106 %N A204691 Numbers n such that n contains exactly 5 digits, all distinct, and n^2 contains exactly 9 distinct digits. %C A204691 There are 30 terms (a(30)=29106); the only prime is a(17)=21397. %t A204691 Select[Range[10000, Sqrt[10^9]], Length[Union[IntegerDigits[#]]] == 5 && Length[Union[IntegerDigits[#^2]]] == 9 &] (* _T. D. Noe_, Jan 18 2012 *) %Y A204691 Subsequence of A054037. %K A204691 base,nonn,fini,full %O A204691 1,1 %A A204691 _Zak Seidov_, Jan 18 2012