|
|
A125946
|
|
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 3,4,5 and at least one of digits 6,7,8,9.
|
|
18
|
|
|
10, 98, 940, 8798, 80140, 709238, 6096100, 50950718, 415060060, 3305238278, 25807024660, 198131841038, 1499550640780, 11213044626518, 82997777543620, 609099122145758, 4437879770746300, 32138240678881958, 231547934781860980, 1661033550903240878
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 24*7^n-72*6^n+98*5^n-76*4^n+35*3^n-9*2^n+1.
G.f.: -2*x*(2520*x^6 -6042*x^5 +6043*x^4 -2783*x^3 +708*x^2 -91*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->24*7^n-72*6^n+98*5^n-76*4^n+35*3^n-9*2^n+1;
|
|
PROG
|
(PARI) vector(100, n, 24*7^n-72*6^n+98*5^n-76*4^n+35*3^n-9*2^n+1) \\ Colin Barker, Feb 23 2015
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|