

A104348


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


2



9, 8, 7, 6, 5, 4, 3, 2, 1, 81, 90, 0, 0, 0, 0, 0, 0, 0, 0, 72, 9, 80, 0, 0, 0, 0, 0, 0, 0, 63, 18, 0, 70, 0, 0, 0, 0, 0, 0, 54, 27, 0, 0, 60, 0, 0, 0, 0, 0, 45, 36, 0, 0, 0, 50, 0, 0, 0, 0, 36, 45, 0, 0, 0, 0, 40, 0, 0, 0, 27, 54, 0, 0, 0, 0, 0, 30, 0, 0, 18, 63, 0, 0, 0, 0, 0, 0, 20, 0, 9, 72, 0, 0, 0
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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(8)=2 because there are only two integers m such that m  (digit reversal of m) = 9*8=72, namely 80 and 91: 80(08)=808=72 and 9119=72.


MATHEMATICA

A104348=Table[Select[Range[0, 40000], (FromDigits[Reverse[IntegerDigits[ # ]]]#)/9==k&]//Length, {k, 100}]


CROSSREFS

Cf. A104347.
Sequence in context: A171816 A083824 A087029 * A251984 A298372 A089186
Adjacent sequences: A104345 A104346 A104347 * A104349 A104350 A104351


KEYWORD

nonn,base


AUTHOR

Zak Seidov, Mar 02 2005


STATUS

approved



