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 1-3 of 3 results.

A307166 Minimum number of loops in a diagonal Latin square of order n.

Original entry on oeis.org

1, 0, 0, 12, 10, 27, 21, 40
Offset: 1

Views

Author

Eduard I. Vatutin, Mar 27 2019

Keywords

Comments

A loop in a Latin square is a sequence of cells v1=L[i1,j1] -> v2=L[i1,j2] -> v1=L[i2,j2] -> ... -> v2=L[im,j1] -> v1=L[i1,j1] of length 2*m that consists of a pair of values {v1, v2}.
For diagonal Latin squares of order 4 all loops are intercalates. - Eduard I. Vatutin, Oct 05 2020
From Eduard I. Vatutin, Oct 26 2020: (Start)
Every intercalate is a partial loop and every partial loop is a loop, so 0 <= A307163(n) <= A307170(n) <= a(n).
0 <= a(n) <= A307167(n).
(End)

Examples

			For example, the square
  2 4 3 5 0 1
  1 0 4 3 2 5
  0 2 5 4 1 3
  5 3 0 1 4 2
  4 5 1 2 3 0
  3 1 2 0 5 4
has a loop
  2 4 . . . .
  . . . . . .
  . 2 . 4 . .
  . . . . . .
  4 . . 2 . .
  . . . . . .
consisting of the sequence of cells L[1,1]=2 -> L[1,2]=4 -> L[3,2]=2 -> L[3,4]=4 -> L[5,4]=2 -> L[5,1]=4 -> L[1,1]=2 with length 6.
The total number of loops for this square is 21.
		

Crossrefs

Extensions

a(8) added by Eduard I. Vatutin, Oct 05 2020

A307170 Minimum number of partial loops in a diagonal Latin square of order n.

Original entry on oeis.org

0, 0, 0, 12, 0, 21, 0, 24
Offset: 1

Views

Author

Eduard I. Vatutin, Mar 27 2019

Keywords

Comments

A loop in a Latin square is a sequence of cells v1=L[i1,j1] -> v2=L[i1,j2] -> v1=L[i2,j2] -> ... -> v2=L[im,j1] -> v1=L[i1,j1] of length 2*m that consists of a pair of values {v1, v2}. A partial loop is a loop with length < 2*n.
From Eduard I. Vatutin, Oct 20 2020: (Start)
Every intercalate is a partial loop and every partial loop is a loop, so 0 <= A307163(n) <= a(n) <= A307166(n).
0 <= a(n) <= A307171(n).
(End)

Examples

			For example, the square
  2 4 3 5 0 1
  1 0 4 3 2 5
  0 2 5 4 1 3
  5 3 0 1 4 2
  4 5 1 2 3 0
  3 1 2 0 5 4
has a loop
  2 4 . . . .
  . . . . . .
  . 2 . 4 . .
  . . . . . .
  4 . . 2 . .
  . . . . . .
consisting of the sequence of cells L[1,1]=2 -> L[1,2]=4 -> L[3,2]=2 -> L[3,4]=4 -> L[5,4]=2 -> L[5,1]=4 -> L[1,1]=2 with length 6 < 12.
The total number of loops for this square is 21, all of which are partial.
		

Crossrefs

Extensions

a(8) added by Eduard I. Vatutin, Oct 05 2020

A307171 Maximum number of partial loops in a diagonal Latin square of order n.

Original entry on oeis.org

0, 0, 0, 12, 8, 21, 53, 112
Offset: 1

Views

Author

Eduard I. Vatutin, Mar 27 2019

Keywords

Comments

A loop in a Latin square is a sequence of cells v1=L[i1,j1] -> v2=L[i1,j2] -> v1=L[i2,j2] -> ... -> v2=L[im,j1] -> v1=L[i1,j1] of length 2*m that consists of a pair of values {v1, v2}. A partial loop is a loop of length < 2*n.

Examples

			For example, the square
  2 4 3 5 0 1
  1 0 4 3 2 5
  0 2 5 4 1 3
  5 3 0 1 4 2
  4 5 1 2 3 0
  3 1 2 0 5 4
has a loop
  2 4 . . . .
  . . . . . .
  . 2 . 4 . .
  . . . . . .
  4 . . 2 . .
  . . . . . .
consisting of the sequence of cells L[1,1]=2 -> L[1,2]=4 -> L[3,2]=2 -> L[3,4]=4 -> L[5,4]=2 -> L[5,1]=4 -> L[1,1]=2 with length 6 < 12.
The total number of loops for this square is 21, all of which are partial.
		

Crossrefs

Extensions

a(8) added by Eduard I. Vatutin, Oct 06 2020
Showing 1-3 of 3 results.