OFFSET
1,2
COMMENTS
The 9 in the definition can also be any other nonzero digit.
LINKS
FORMULA
G.f.: x*(1 + 8*x)*(1 + 9*x)/(1 - x - 9*x^2 - 81*x^3). - Andrew Howroyd, Oct 20 2024
EXAMPLE
The a(1) = 1 number is 9.
The a(2) = 18 numbers are 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99.
PROG
(PARI) Vec((1 + 8*x)*(1 + 9*x)/(1 - x - 9*x^2 - 81*x^3) + O(x^25)) \\ Andrew Howroyd, Oct 20 2024
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Edwin McCravy, Oct 19 2024
EXTENSIONS
a(9) onwards from Andrew Howroyd, Oct 20 2024
STATUS
approved