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A126643 a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3,4, at least one of digits 5,6 and at least one of digits 7,8,9. 1
6, 34, 180, 886, 4116, 18334, 79260, 335446, 1398276, 5765134, 23581740, 95900806, 388345236, 1567647934, 6313474620, 25382710966, 101917608996, 408831386734, 1638809709900, 6565693949926, 26294146373556, 105270707701534 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

FORMULA

a(n)=6*4^n-9*3^n+5*2^n-1

EXAMPLE

a(8)=335446

MAPLE

f:=n->6*4^n-9*3^n+5*2^n-1;

CROSSREFS

Cf. A125630, A125948, A125947, A125946, A125945, A125940, A125909, A125908, A125880, A125897, A125904, A125858.

Sequence in context: A009469 A198765 A144142 * A084775 A085351 A125343

Adjacent sequences:  A126640 A126641 A126642 * A126644 A126645 A126646

KEYWORD

nonn,base

AUTHOR

Aleksandar M. Janjic and Milan R. Janjic (agnus(AT)blic.net), Feb 08 2007

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Last modified February 17 22:48 EST 2012. Contains 206085 sequences.