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 A043510 #13 Sep 01 2021 16:49:26 %S A043510 55,155,255,355,455,505,515,525,535,545,550,551,552,553,554,556,557, %T A043510 558,559,565,575,585,595,655,755,855,955,1055,1155,1255,1355,1455, %U A043510 1505,1515,1525,1535,1545,1550,1551,1552,1553,1554,1556 %N A043510 Numbers having two 5's in base 10. %H A043510 Daniel Starodubtsev, <a href="/A043510/b043510.txt">Table of n, a(n) for n = 1..10000</a> %t A043510 Select[Range[1600],DigitCount[#,10,5]==2&] (* _Harvey P. Dale_, Sep 01 2021 *) %Y A043510 Subsequence of A011535. %K A043510 nonn,base %O A043510 1,1 %A A043510 _Clark Kimberling_