A341191 Number of ways to write n as an ordered sum of 2 nonzero decimal palindromes.

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, 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, 2, 2, 2, 2, 2, 2, 0, 6, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 7, 2, 2

Offset: 2

Author

Ilya Gutkovskiy, Feb 06 2021

Keywords

• nonn
• base

Links

• Alois P. Heinz, Table of n, a(n) for n = 2..20000

Crossrefs

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

Programs

Mathematica

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