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Palindromes of form k^2 + k + 1.
4

%I #13 Aug 11 2024 14:41:29

%S 1,3,7,111,343,757,10101,15751,30103,1001001,1255521,1403041,1837381,

%T 3372733,3521253,3847483,100010001,141979141,10000100001,14181118141,

%U 16112621161,35297579253,35475157453,37011411073,38735553783,1000001000001,1020505050201

%N Palindromes of form k^2 + k + 1.

%H Giovanni Resta, <a href="/A028414/b028414.txt">Table of n, a(n) for n = 1..68</a>

%H P. De Geest, <a href="https://www.worldofnumbers.com/quasisq.htm">Palindromic quasi_over_squares of the form n^2+(n+1)</a>

%t palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 1; Select[f@ Range[0, 10^5], palQ] (* _Giovanni Resta_, Aug 29 2018 *)

%Y Cf. A028413, A028337, A027713.

%K nonn,base

%O 1,2

%A _Patrick De Geest_

%E More terms from _Giovanni Resta_, Aug 28 2018