A341206 Number of ways to write n as an ordered sum of 9 nonzero decimal palindromes.

1, 9, 45, 165, 495, 1287, 3003, 6435, 12870, 24301, 43686, 75249, 124809, 200115, 311157, 470415, 693000, 996633, 1401436, 1929465, 2603979, 3448440, 4485267, 5734395, 7211718, 8927523, 10885050, 13079257, 15496065, 18112050, 20894757, 23803659, 26791749, 29807697, 32798448

Offset

9,2

Links

Alois P. Heinz, Table of n, a(n) for n = 9..10000

Maple

p:= proc(n) option remember; local i, s; s:= ""||n;
      for i to iquo(length(s), 2) do if
        s[i]<>s[-i] then return false fi od; true
    end:
b:= proc(n, t) option remember; `if`(n=0, `if`(t=0, 1, 0),
      `if`(t<1, 0, add(`if`(p(j), b(n-j, t-1), 0), j=1..n)))
    end:
a:= n-> b(n, 9):
seq(a(n), n=9..43);  # Alois P. Heinz, Feb 07 2021

Mathematica

nmax = 43; CoefficientList[Series[Sum[Boole[PalindromeQ[k]] x^k, {k, 1, nmax}]^9, {x, 0, nmax}], x] // Drop[#, 9] &

Crossrefs

Cf. A002113, A136522, A319474, A341167, A341184, A341191, A341192, A341193, A341203, A341204, A341205, A341207.

Sequence in context: A247609 A341138 A008501 * A306942 A289354 A008491

Adjacent sequences: A341203 A341204 A341205 * A341207 A341208 A341209

Keyword

nonn,base

Author

Ilya Gutkovskiy, Feb 06 2021

Status

approved