OFFSET
1,2
COMMENTS
There are 900000000 numbers with 9 decimal digits, the smallest being 100000000 and the largest 999999999.
LINKS
Miquel Cerda, Table of n, a(n) for n = 1..81
FORMULA
a(n) = a(82 - n). - David A. Corneth, Jul 03 2017
G.f.: (x - x^10)/(1 - x)*((1 - x^10)/(1 - x))^8 - Michael De Vlieger, Jul 04 2017
EXAMPLE
a(2)=9: 100000001, 100000010, 100000100, 100001000, 100010000, 100100000, 101000000, 11000000, 20000000.
MATHEMATICA
With[{d = 9}, Rest@ CoefficientList[Series[(x - x^10)/(1 - x) ((1 - x^10)/(1 - x))^(d - 1), {x, 0, 9 d}], x]] (* Michael De Vlieger, Jul 04 2017 *)
CROSSREFS
KEYWORD
base,fini,full,nonn
AUTHOR
Miquel Cerda, Jul 03 2017
STATUS
approved