login
Numbers k such that k^2+k+2 is a palindrome.
4

%I #14 Aug 11 2024 14:41:29

%S 0,1,2,4,6,14,15,21,50,92,201,203,292,479,897,1424,1530,1654,2001,

%T 2106,2183,16780,20001,20993,28377,89777,200001,219083,501474,1620660,

%U 1651754,2000001,14842995,17101809,20000001,21147906,21855108,22012038,29287052

%N Numbers k such that k^2+k+2 is a palindrome.

%H Giovanni Resta, <a href="/A027712/b027712.txt">Table of n, a(n) for n = 1..65</a>

%H P. De Geest, <a href="https://www.worldofnumbers.com/quasimor.htm">Palindromic Quasi_Over_Squares of the form n^2+(n+X)</a>

%t palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 2; Select[Range[0, 10^5], palQ@ f@ # &] (* _Giovanni Resta_, Aug 29 2018 *)

%Y Cf. A027713, A014206, A028413, A027714.

%K nonn,base

%O 1,3

%A _Patrick De Geest_

%E More terms from _Giovanni Resta_, Aug 28 2018