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: Jean-Luc Manguin

Jean-Luc Manguin's wiki page.

Jean-Luc Manguin has authored 3 sequences.

A335014 Row sums of A331462.

Original entry on oeis.org

0, 1, 4, 45, 1524, 290088, 216542974
Offset: 0

Views

Author

Jean-Luc Manguin, May 19 2020

Keywords

Crossrefs

Row sums of A331462.
Cf. A054247.

A336267 Number of free polyominoes of width 3 and height n.

Original entry on oeis.org

1, 6, 24, 181, 941, 4662, 23691, 119271, 603760, 3050402, 15428576, 78004550, 394462578, 1994595585, 10086050889, 51001111356, 257894037378, 1304071170194, 6594196094078, 33344335235915, 168609627579175, 852594638783225, 4311246376730011
Offset: 1

Views

Author

Jean-Luc Manguin, Jul 15 2020

Keywords

Comments

The sequence can be generated using a series of recursive formulas in a fashion similar to A353067. - John Mason, Nov 04 2022

Examples

			a(2)=6, bounding box 2 X 3 as in A335711.

Links

Crossrefs

Cf. A268371, A335711, A353067.

Extensions

More terms from John Mason, Nov 04 2022

A331462 Triangle read by rows: T(n,k) is the number of n X n binary matrices with k=0..n^2 ones forming a polyomino, under action of dihedral group of the square D_4.

Original entry on oeis.org

0, 0, 1, 0, 1, 1, 1, 1, 0, 3, 2, 5, 6, 10, 8, 7, 3, 1, 0, 3, 4, 8, 17, 33, 68, 119, 195, 261, 300, 257, 169, 66, 20, 3, 1, 0, 6, 6, 16, 32, 82, 189, 470, 1076, 2422, 5010, 9732, 17145, 27399, 38680, 47560, 49325, 41872, 27864, 14095, 5280, 1470, 302, 48, 6, 1
Offset: 0

Views

Author

Jean-Luc Manguin, Jan 17 2020

Keywords

Comments

By forming a polyomino it is meant that there is at least one 1 and that all the 1's are connected horizontally or vertically.

Examples

			Triangle begins:
  0;
  0, 1;
  0, 1, 1, 1, 1;
  0, 3, 2, 5, 6, 10, 8, 7, 3, 1;
  0, 3, 4, 8, 17, 33, 68, 119, 195, 261, 300, 257, 169, 66, 20, 3, 1;
  ...

Links

Crossrefs

Cf. A054252, A268416.

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