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.

Showing 1-2 of 2 results.

A370568 Expansion of g.f. (1-x) / (1-9*x+28*x^2-35*x^3+15*x^4-x^5).

Original entry on oeis.org

1, 8, 44, 207, 896, 3689, 14706, 57361, 220363, 837430, 3157440, 11835916, 44176890, 164355675, 609981045, 2259680355, 8359285126, 30890694534, 114059719703, 420887785505, 1552362630016, 5723494732725, 21096366345741, 77742879583057, 286445422547405
Offset: 0

Views

Author

Peter Morris, Feb 22 2024

Keywords

Comments

The sequence is constructed from a truncated version of Pascal's Triangle. See A370074 for an example. a(n) arises from the Gambler's Ruin problem and represents the number of ways a gambler is ruined after starting with $8 with a maximum $11 causing retirement.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{9, -28, 35, -15, 1}, {1, 8, 44, 207, 896}, 25] (* Paolo Xausa, Jun 09 2024 *)

Formula

a(n) = 9*a(n-1)-28*a(n-2)+35*a(n-3)-15*a(n-4)+a(n-5) for n>=5.

A370391 Expansion of (1 - 2*x)/(1 - 9*x + 28*x^2 - 35*x^3 + 15*x^4 - x^5).

Original entry on oeis.org

1, 7, 35, 154, 636, 2533, 9861, 37810, 143451, 540155, 2022735, 7543771, 28048829, 104050724, 385320419, 1425038684, 5264963100, 19437087382, 71715418017, 264483764116, 975070823122, 3593840295815, 13243217176106, 48793364067681, 179753027448972
Offset: 0

Views

Author

Peter Morris, Feb 22 2024

Keywords

Comments

The sequence is constructed by a truncated version of Pascal's Triangle.
1
1 1
1 2 1
1 3 3 1
1 4 6 4
1 5 10 10 4
1 6 15 20 14
7 21 35 34 14
7 28 56 69 48
35 84 125 117 48
35 119 209 242 165
...
After truncation the sequence appears as the left vertical column. The right column sequence can be in A370051.
a(n) arises from the Gambler's Ruin problem and represents the number of ways a gambler is ruined after starting with $7 with a maximum $11 causing retirement.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{9, -28, 35, -15, 1}, {1, 7,35,154,636}, 25] (* James C. McMahon, Mar 12 2024 *)

Formula

a(n) = 9*a(n-1) - 28*a(n-2) + 35*a(n-3) - 15*a(n-4) + a(n-5).
Showing 1-2 of 2 results.