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.

User: Matthias Fresacher

Matthias Fresacher's wiki page.

Matthias Fresacher has authored 2 sequences.

A373011 Number of congruences of the 0-twisted Temperley-Lieb monoid of degree n.

Original entry on oeis.org

2, 2, 3, 3, 7, 4, 8, 5, 9, 6, 10, 7, 11, 8, 12, 9, 13, 10, 14, 11, 15, 12, 16, 13, 17, 14, 18, 15, 19, 16, 20, 17, 21, 18, 22, 19, 23, 20, 24, 21, 25, 22, 26, 23, 27, 24, 28, 25, 29, 26, 30, 27, 31, 28, 32, 29, 33, 30, 34, 31, 35, 32, 36, 33, 37, 34, 38, 35
Offset: 0

Author

Matthias Fresacher, May 23 2024

Keywords

Crossrefs

Closely related to A368923.

Programs

  • Mathematica
    LinearRecurrence[{1, 1, -1}, {2, 2, 3, 3, 7, 4}, 100] (* Paolo Xausa, Aug 07 2024 *)
  • PARI
    a(n)=if(n%2, (n+3)/2, n>2, n/2+5, n/2+2) \\ Charles R Greathouse IV, Aug 07 2024

Formula

a(n) = (n + 3)/2 if n is odd.
a(n) = (n + 10)/2 if n is even and n >= 4.
a(n) = a(n-2) + 1 for n >= 5.

A368923 Number of congruences of the 0-twisted Brauer monoid of degree n.

Original entry on oeis.org

2, 2, 5, 5, 13, 8, 16, 11, 19, 14, 22, 17, 25, 20, 28, 23, 31, 26, 34, 29, 37, 32, 40, 35, 43, 38, 46, 41, 49, 44, 52, 47, 55, 50, 58, 53, 61, 56, 64, 59, 67, 62, 70, 65, 73, 68, 76, 71, 79, 74, 82, 77, 85, 80, 88, 83, 91, 86, 94, 89, 97, 92, 100, 95, 103, 98, 106, 101, 109
Offset: 0

Author

Matthias Fresacher, Jan 09 2024

Keywords

Crossrefs

Essentially the same as A147677.
Cf. A008585.
Closely related to A373011.

Programs

  • Mathematica
    LinearRecurrence[{1, 1, -1}, {2, 2, 5, 5, 13, 8}, 100] (* Paolo Xausa, Feb 27 2024 *)

Formula

a(n) = (3*n + 1)/2 if n is odd.
a(n) = (3*n + 14)/2 if n is even and n >= 4.
a(n) = a(n-2) + 3 for n >= 5.
G.f.: -(5*x^5-5*x^4-x^2-2)/((x+1)*(x-1)^2).
a(n) = A147677(n+1) for n >= 3.