

A160154


10^n9n for n>=1


0



0, 1, 82, 973, 9964, 99955, 999946, 9999937, 99999928, 999999919, 9999999910, 99999999901, 999999999892, 9999999999883, 99999999999874, 999999999999865, 9999999999999856, 99999999999999847, 999999999999999838
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OFFSET

0,3


COMMENTS

a(n) is the number of positive integers less than or equal to 10^n that have at least two distinct digits.


REFERENCES

Miklos Bona, Introduction to Enumerative Combinatorics, McGrawHill,2007,p.5


LINKS

Table of n, a(n) for n=0..18.


FORMULA

O.g.f.: (x+70x^2+10x^3)/((1x)^2*(110x)) E.g.f.: exp(10x)9x*exp(x)1


MATHEMATICA

CoefficientList[Series[Exp[10 x]  9 x*Exp[x]  1, {x, 0, 20}], x]* Table[n!, {n, 0, 20}]


CROSSREFS

For n>=1, a(n)=A011557A008591
Sequence in context: A083386 A282159 A263812 * A093282 A085439 A282155
Adjacent sequences: A160151 A160152 A160153 * A160155 A160156 A160157


KEYWORD

nonn


AUTHOR

Geoffrey Critzer, May 03 2009


STATUS

approved



