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 A027715 #14 Aug 11 2024 14:41:29
%S A027715 3,5,9,33,383,555,3663,5115,30803,32223,34043,59295,567765,5912195,
%T A027715 37877873,534141435,957747759,5356556535,5646996465,53205650235,
%U A027715 56511511565,358023320853,9571923291759,30171944917103,309961535169903,356681959186653,955371999173559
%N A027715 Palindromes of form k^2 + k + 3.
%C A027715 Palindromes h such that 4*h - 11 is a square. - _Bruno Berselli_, Aug 29 2018
%H A027715 Giovanni Resta, <a href="/A027715/b027715.txt">Table of n, a(n) for n = 1..50</a>
%H A027715 P. De Geest, <a href="https://www.worldofnumbers.com/quasimor.htm">Palindromic Quasi_Over_Squares of the form n^2+(n+X)</a>
%t A027715 palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 3; Select[f@ Range[0, 10^5], palQ] (* _Giovanni Resta_, Aug 29 2018 *)
%Y A027715 Cf. A027714, A027688, A027752, A027753, A027713, A027717.
%K A027715 nonn,base
%O A027715 1,1
%A A027715 _Patrick De Geest_
%E A027715 More terms from _Giovanni Resta_, Aug 29 2018