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Palindromes of form k^2 + k + 2.
5

%I #25 Sep 08 2022 08:44:49

%S 2,4,8,22,44,212,242,464,2552,8558,40604,41414,85558,229922,805508,

%T 2029202,2342432,2737372,4006004,4437344,4767674,281585182,400060004,

%U 440727044,805282508,8059999508,40000600004,47997579974,251476674152,2626540456262,2728292928272

%N Palindromes of form k^2 + k + 2.

%C Palindromes h such that 4*h - 7 is a square. - _Bruno Berselli_, Aug 29 2018

%H Giovanni Resta, <a href="/A027713/b027713.txt">Table of n, a(n) for n = 1..65</a>

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

%t palQ[n_] := Module[{idn = IntegerDigits[n]}, idn == Reverse[idn]]; Select[Table[n^2 + n + 2, {n, 0, 502000}], palQ] (* _Harvey P. Dale_, Sep 15 2011 *)

%o (Magma) [m: n in [0..10^7] | Intseq(m) eq Reverse(Intseq(m)) where m is n^2+n+2]; // _Vincenzo Librandi_, Mar 27 2011

%Y Cf. A014206, A027712, A028414, A027715.

%K nonn,base

%O 1,1

%A _Patrick De Geest_

%E More terms from _Giovanni Resta_, Aug 28 2018