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Number of ways to write n as an ordered sum of 2 nonzero decimal palindromes.
9

%I #7 Feb 07 2021 13:12:18

%S 1,2,3,4,5,6,7,8,9,8,9,8,7,6,5,4,3,2,2,0,1,2,2,2,2,2,2,2,2,2,0,2,2,2,

%T 2,2,2,2,2,2,2,0,3,2,2,2,2,2,2,2,2,2,0,4,2,2,2,2,2,2,2,2,2,0,5,2,2,2,

%U 2,2,2,2,2,2,0,6,2,2,2,2,2,2,2,2,2,0,7,2,2

%N Number of ways to write n as an ordered sum of 2 nonzero decimal palindromes.

%H Alois P. Heinz, <a href="/A341191/b341191.txt">Table of n, a(n) for n = 2..20000</a>

%t nmax = 90; CoefficientList[Series[Sum[Boole[PalindromeQ[k]] x^k, {k, 1, nmax}]^2, {x, 0, nmax}], x] // Drop[#, 2] &

%Y Cf. A002113, A136522, A260254, A319468, A341155, A341192, A341193.

%K nonn,base

%O 2,2

%A _Ilya Gutkovskiy_, Feb 06 2021