|
|
A125897
|
|
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 the digits 1,2,3 and at least one of the digits 4,5,6,7,8,9.
|
|
18
|
|
|
10, 100, 994, 9796, 95650, 924820, 8845714, 83575396, 778945090, 7156197940, 64800104434, 578648865796, 5100362368930, 44424892053460, 382839350691154, 3268062540952996, 27665402010407170, 232490197792427380, 1941315874498269874
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 18*8^n-63*7^n+111*6^n-120*5^n+83*4^n-36*3^n+9*2^n-1.
G.f.: -2*x*(20160*x^7 -54792*x^6 +53344*x^5 -28304*x^4 +8374*x^3 -1427*x^2 +130*x -5) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)*(7*x -1)*(8*x -1)). - Colin Barker, Feb 23 2015
|
|
MAPLE
|
f:=n->18*8^n-63*7^n+111*6^n-120*5^n+83*4^n-36*3^n+9*2^n-1;
|
|
PROG
|
(PARI) vector(100, n, 18*8^n-63*7^n+111*6^n-120*5^n+83*4^n-36*3^n+9*2^n-1) \\ Colin Barker, Feb 23 2015
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|