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A126635 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3, at least one of digits 4,5 and at least one of digits 6,7,8,9. 3
7, 47, 307, 1943, 11827, 69287, 392707, 2166743, 11703187, 62168327, 325983907, 1692105143, 8714154547, 44600020967, 227161443907, 1152585909143, 5830444893907, 29423488811207, 148206112628707, 745396075770743, 3744474953809267, 18792450661083047 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = 8*5^n-16*4^n+14*3^n-6*2^n+1.
G.f.: -x*(120*x^4-242*x^3+197*x^2-58*x+7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)). - Colin Barker, Feb 22 2015
MAPLE
f:=n->8*5^n-16*4^n+14*3^n-6*2^n+1;
MATHEMATICA
LinearRecurrence[{15, -85, 225, -274, 120}, {7, 47, 307, 1943, 11827}, 30] (* Harvey P. Dale, Dec 31 2021 *)
PROG
(PARI) Vec(-x*(120*x^4-242*x^3+197*x^2-58*x+7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015
CROSSREFS
Sequence in context: A198845 A323131 A229010 * A085352 A125370 A163346
KEYWORD
nonn,base,easy
AUTHOR
Aleksandar M. Janjic and Milan Janjic, Feb 08 2007
STATUS
approved

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Last modified May 23 04:41 EDT 2024. Contains 372758 sequences. (Running on oeis4.)