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 A028559 #25 May 05 2024 08:55:57 %S A028559 0,6,66,414,696,41814,42224,666666,4282824,4754574,4881884,416343614, %T A028559 630939036,4159669514,6817557186,42877777824,4163250523614, %U A028559 4783601063874,4986733376894,47431877813474,6333914444193336,44653247574235644,62141509790514126 %N A028559 Palindromes of the form k*(k+5). %H A028559 Lior Manor, <a href="/A028559/b028559.txt">Table of n, a(n) for n = 1..33</a> (terms 1..27 from Michael S. Branicky) %H A028559 Patrick De Geest, <a href="http://www.worldofnumbers.com/consemor.htm">Palindromic Quasipronics of the form n(n+x)</a> %F A028559 a(n) = A028558(n) * (A028558(n) + 5). - _Michael S. Branicky_, Jan 30 2022 %o A028559 (Python) %o A028559 from itertools import count, islice %o A028559 def ispal(n): s = str(n); return s == s[::-1] %o A028559 def agen(): %o A028559 for k in count(0): %o A028559 if ispal(k*(k+5)): %o A028559 yield k*(k+5) %o A028559 print(list(islice(agen(), 20))) # _Michael S. Branicky_, Jan 30 2022 %Y A028559 Cf. A028557, A028558. %K A028559 nonn,base %O A028559 1,2 %A A028559 _Patrick De Geest_ %E A028559 a(21) and beyond from _Michael S. Branicky_, Jan 30 2022