login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A086580 a(n) = 9*(10^n - 1). 9
0, 81, 891, 8991, 89991, 899991, 8999991, 89999991, 899999991, 8999999991, 89999999991, 899999999991, 8999999999991, 89999999999991, 899999999999991, 8999999999999991, 89999999999999991, 899999999999999991, 8999999999999999991, 89999999999999999991, 899999999999999999991 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Original definition: a(n) = k where R(k+9) = 9.
LINKS
FORMULA
a(n) = 9*9*A002275(n) = 9*A002283(n).
R(a(n)) = A086573(n).
From Chai Wah Wu, Jul 08 2016: (Start)
a(n) = 11*a(n-1) - 10*a(n-2) for n > 1.
G.f.: 81*x/((1 - x)*(1 - 10*x)). (End)
MATHEMATICA
Table[9*(10^n-1), {n, 0, 30}] (* G. C. Greubel, Jul 07 2023 *)
PROG
(Magma) [9*(10^n -1): n in [0..30]]; // G. C. Greubel, Jul 07 2023
(SageMath)
A086580=BinaryRecurrenceSequence(11, -10, 0, 81)
[A086580(n) for n in range(30)] # G. C. Greubel, Jul 07 2023
CROSSREFS
Cf. A004086 (R(n)).
One of family of sequences of form a(n) = k, where R(k+m) = m, m=1 to 9; m=1: A002283, m=2: A086573, m=3: A086574, m=4: A086575, m=5: A086576, m=6: A086577, m=7: A086578, m=8: A086579, m=9: A086580.
Sequence in context: A222995 A173810 A205047 * A206269 A236885 A205729
KEYWORD
nonn,base
AUTHOR
Ray Chandler, Jul 22 2003
EXTENSIONS
Name edited by Jinyuan Wang, Aug 04 2021
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)