A104347 a(n) is the number of integers m such that (digit reversal of m) - m = 9*n.

8, 7, 6, 5, 4, 3, 2, 1, 0, 81, 80, 0, 0, 0, 0, 0, 0, 0, 0, 72, 8, 70, 0, 0, 0, 0, 0, 0, 0, 63, 16, 0, 60, 0, 0, 0, 0, 0, 0, 54, 24, 0, 0, 50, 0, 0, 0, 0, 0, 45, 32, 0, 0, 0, 40, 0, 0, 0, 0, 36, 40, 0, 0, 0, 0, 30, 0, 0, 0, 27, 48, 0, 0, 0, 0, 0, 20, 0, 0, 18, 56, 0, 0, 0, 0, 0, 0, 10, 0, 9, 64, 0, 0, 0

Offset

1,1

Comments

For any n>0, a(n) is finite (or zero) and a(0) is infinite (because there are an infinite number of palindromes).

Links

Table of n, a(n) for n=1..94.

Example

a(7)=2 because there are only two integers m such that (digit reversal of m) - m = 9*7=63, namely 18 and 29: 81-18=63 and 92-29=63.

Mathematica

A104347=Table[Select[Range[0, 40000], (FromDigits[Reverse[IntegerDigits[ # ]]]-#)/9==k&]//Length, {k, 100}]

Crossrefs

Cf. A104348.

Sequence in context: A031310 A161813 A284809 * A180598 A262703 A031311

Adjacent sequences: A104344 A104345 A104346 * A104348 A104349 A104350

Keyword

nonn,base

Author

Zak Seidov, Mar 02 2005

Status

approved