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Positive integers k that k^2 is a palindrome not containing a 0 digit.
0

%I #17 Jul 01 2018 10:33:04

%S 1,2,3,11,22,26,111,121,212,264,307,836,1111,2285,2636,11011,11111,

%T 11211,24846,111111,798644,1101011,1102011,1110111,1111111,2294675,

%U 11011011,11100111,11111111,11129361,12028229,12866669,110101011,110111011,111010111

%N Positive integers k that k^2 is a palindrome not containing a 0 digit.

%e 264 is in the sequence because 264^2 = 69696, which is a palindrome.

%t palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse@d]; Select[ Range[10^6], Min@ IntegerDigits[#^2] > 0 && palQ[#^2] &] (* _Giovanni Resta_, Jun 27 2018 *)

%o (PARI) is(n) = my(d=digits(n^2)); d==Vecrev(d) && vecmin(d) > 0 \\ _Felix Fröhlich_, Jun 29 2018

%Y Subsequence of A002778.

%K nonn,base

%O 1,2

%A _Thana Somsirivattana_, Jun 26 2018

%E a(14)-a(35) from _Giovanni Resta_, Jun 27 2018