cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A161770 n 1's followed by three 0's.

Original entry on oeis.org

1000, 11000, 111000, 1111000, 11111000, 111111000, 1111111000, 11111111000, 111111111000, 1111111111000, 11111111111000, 111111111111000, 1111111111111000, 11111111111111000, 111111111111111000, 1111111111111111000, 11111111111111111000, 111111111111111111000
Offset: 1

Views

Author

Jaroslav Krizek, Jun 18 2009

Keywords

Comments

Sequence A159741 written in base 2.

Crossrefs

Programs

  • Mathematica
    Table[FromDigits[PadLeft[{0,0,0},n,1]],{n,4,20}] (* Harvey P. Dale, Aug 07 2023 *)

Formula

a(n) = 1000*(10^n - 1)/9 = 1000*A002275(n).
G.f.: 1000*x/((10*x-1)*(x-1)).
From Elmo R. Oliveira, Jun 18 2025: (Start)
E.g.f.: 1000*exp(x)*(exp(9*x) - 1)/9.
a(n) = 100*A105279(n) = 10*A124166(n).
a(n) = 11*a(n-1) - 10*a(n-2) for n > 2. (End)

Extensions

Edited by Charles R Greathouse IV, Oct 12 2009