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A114120 Palindromes which are not the arithmetic mean of two distinct positive palindromes. 1

%I #21 Sep 29 2020 07:45:41

%S 1,11,10901,109901,1090901,1099901,10900901,10999901,100909001,

%T 109000901,109090901,109909901,109999901,1090000901,1090990901,

%U 1099009901,1099999901,10090909001,10900000901,10900900901,10909090901,10909990901

%N Palindromes which are not the arithmetic mean of two distinct positive palindromes.

%C In this sequence 0 is not allowed as an addend. If 0 were allowed then 0 would be a term and 1 and 11 would not. - _Yuan-Hao Huang_, Aug 31 2020

%e 191 is not in the sequence since it is the arithmetic mean of two distinct positive palindromes, 9 and 373.

%Y Cf. A002113, A083158.

%K base,nonn

%O 1,2

%A _Giovanni Resta_, Feb 06 2006

%E a(1)=1 inserted by _Yuan-Hao Huang_, Aug 31 2020

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Last modified April 18 15:48 EDT 2024. Contains 371780 sequences. (Running on oeis4.)