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A125630 a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digit 1 and at least one of digits 2,3,4,5,6,7,8,9. 29
9, 81, 729, 6561, 59049, 531441, 4782969, 43006401, 385606089, 3440214801, 30482931609, 267934415841, 2334817386729, 20170171738161, 172797111134649, 1468818073594881, 12396189742824969, 103943773544221521 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Note that the first seven terms of the sequence are powers of 9.

LINKS

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

FORMULA

f(n)=8*8^n-28*7^n+56*6^n-70*5^n+56*4^n-28*3^n+8*2^n-1.

EXAMPLE

f(5)=59049

MAPLE

f:=n->8*8^n-28*7^n+56*6^n-70*5^n+56*4^n-28*3^n+8*2^n-1;

CROSSREFS

Sequence in context: A174108 A125947 A120997 * A100062 A001019 A074118

Adjacent sequences:  A125627 A125628 A125629 * A125631 A125632 A125633

KEYWORD

nonn,base

AUTHOR

Aleksandar M. Janjic and Milan R. Janjic (agnus(AT)blic.net), Jan 28 2007, Feb 13 2007

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Last modified February 14 16:28 EST 2012. Contains 205635 sequences.