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 A307827 #9 Aug 11 2024 14:41:35 %S A307827 0,1,232,27972,76867,25555552,7154664517,158229922851,2028787878202, %T A307827 2040061600402,2733623263372,52667666676625,675972505279576, %U A307827 28519896169891582,73542836563824537,74529570707592547,25552469511596425552,27835145788754153872 %N A307827 Palindromic decagonal (or 10-gonal) numbers. %H A307827 Robert Price, <a href="/A307827/b307827.txt">Table of n, a(n) for n = 1..22</a> %H A307827 P. De Geest, <a href="https://www.worldofnumbers.com/nona.htm">Palindromic nonagonals</a> %t A307827 Select[PolygonalNumber[10, Range[0, 10^5]], PalindromeQ] %Y A307827 Cf. A001107, A082723. %K A307827 nonn,base %O A307827 1,3 %A A307827 _Robert Price_, Apr 30 2019