|
%I #16 Sep 08 2022 08:44:50
%S 1,5,11,55,131,181,505,929,1331,9119,10301,14041,15251,106601,145541,
%T 196691,1003001,1284821,1712171,9452549,100030001,106636601,112434211,
%U 160111061,174464471,924494429,950828059,990707099,1067557601,9140220419,9300770039
%N Palindromes of form n^2 + 3*n + 1.
%H G. C. Greubel, <a href="/A028349/b028349.txt">Table of n, a(n) for n = 1..49</a>
%H P. De Geest, <a href="http://www.worldofnumbers.com/sumpower.htm">Palindromic Quasi_Under_Squares of the form n+(n+1)^2</a>
%t PalindromeQ = ((# // IntegerDigits // Reverse // FromDigits) == #) &; Select[Table[n^2 + 3*n + 1, {n, 1, 5000}], PalindromeQ] (* _G. C. Greubel_, Nov 26 2016 *)
%o (Magma) [p: n in [0..100000] | s eq Reverse(s) where s is Intseq(p) where p is n^2+3*n+1]; // _Vincenzo Librandi_, Nov 26 2016
%Y Cf. A028348.
%K nonn,base
%O 1,2
%A _Patrick De Geest_
%E Name corrected and sequence extended by _T. D. Noe_, Apr 17 2012
|
