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A125945 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks at least one of digits 1,2, at least one of digits 3,4 and at least one of digits 5,6,7,8,9. 19
10, 96, 892, 8076, 71500, 619236, 5241652, 43355436, 350740540, 2780210676, 21641505412, 165814383996, 1253254845580, 9362782430916, 69259450905172, 508062802935756, 3700662365318620, 26794126632247956, 193018363703408932, 1384505203965202716 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (28,-322,1960,-6769,13132,-13068,5040).
FORMULA
a(n) = 20*7^n-60*6^n+85*5^n-70*4^n+34*3^n-9*2^n+1.
G.f.: -2*x*(2520*x^6 -6054*x^5 +6063*x^4 -2794*x^3 +712*x^2 -92*x +5) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)*(7*x -1)). - Colin Barker, Feb 23 2015
MAPLE
f:=n->20*7^n-60*6^n+85*5^n-70*4^n+34*3^n-9*2^n+1;
PROG
(PARI) a(n)=20*7^n-60*6^n+85*5^n-70*4^n+34*3^n-9*2^n+1 \\ Charles R Greathouse IV, Sep 24 2015
CROSSREFS
Cf. A125630.
Sequence in context: A197083 A197086 A278359 * A259497 A190986 A287831
KEYWORD
nonn,base,easy
AUTHOR
Aleksandar M. Janjic and Milan Janjic, Feb 04 2007
STATUS
approved

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Last modified April 12 19:05 EDT 2024. Contains 371636 sequences. (Running on oeis4.)