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A126629 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks digits 1 and 2, at least one of digits 3,4,5 and at least one of digits 6,7,8,9. 2
8, 64, 506, 3916, 29498, 215524, 1527506, 10528876, 70841738, 467044084, 3027621506, 19356463036, 122355512378, 766290978244, 4762898595506, 29420807536396, 180813134269418, 1106606890266004, 6749433735297506, 41050188511748956, 249087606867080858 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

Index entries for linear recurrences with constant coefficients, signature (21,-175,735,-1624,1764,-720).

FORMULA

a(n) = 12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1.

G.f.: -2*x*(360*x^5 -882*x^4 +695*x^3 -281*x^2 +52*x -4) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)). - Colin Barker, Feb 23 2015

MAPLE

f:=n->12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1;

MATHEMATICA

LinearRecurrence[{21, -175, 735, -1624, 1764, -720}, {8, 64, 506, 3916, 29498, 215524}, 30] (* Harvey P. Dale, Sep 26 2019 *)

PROG

(PARI) vector(100, n, 12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1) \\ Colin Barker, Feb 23 2015

CROSSREFS

Cf. A125630, A125948, A125947, A125946, A125945, A125910, A125909, A125908, A125880, A125897, A125904, A125858.

Sequence in context: A269466 A127426 A268456 * A250350 A171282 A125498

Adjacent sequences:  A126626 A126627 A126628 * A126630 A126631 A126632

KEYWORD

nonn,base,easy

AUTHOR

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

STATUS

approved

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Last modified June 25 13:19 EDT 2022. Contains 354851 sequences. (Running on oeis4.)