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.

A221270 Number of n X 2 arrays of occupancy after each element moves to some king-move neighbor, with every occupancy equal to zero or two.

Original entry on oeis.org

0, 6, 16, 52, 174, 588, 1984, 6688, 22536, 75924, 255760, 861496, 2901696, 9773184, 32916280, 110861104, 373373568, 1257492096, 4235114944, 14263430416, 48037679232, 161785483872, 544874848384, 1835074738624, 6180315022560
Offset: 1

Views

Author

R. H. Hardin, Jan 08 2013

Keywords

Comments

Column 2 of A221273.

Examples

			Some solutions for n=4:
..0..2....0..0....0..2....2..0....0..2....2..0....0..0....0..2....2..2....0..0
..2..2....0..2....2..0....2..0....0..2....0..2....2..2....0..2....0..0....2..2
..0..2....2..0....2..0....0..2....0..2....2..0....0..2....0..0....0..0....2..0
..0..0....2..2....2..0....2..0....0..2....0..2....2..0....2..2....2..2....2..0

Links

Crossrefs

Cf. A221273.

Formula

Empirical: a(n) = 6*a(n-1) - 10*a(n-2) + 4*a(n-3) - 2*a(n-5).
Empirical g.f.: 2*x^2*(1 - x)*(3 - 7*x + x^2) / (1 - 6*x + 10*x^2 - 4*x^3 + 2*x^5). - Colin Barker, Mar 14 2018

A221271 Number of nX3 arrays of occupancy after each element moves to some king-move neighbor, with every occupancy equal to zero or two.

Original entry on oeis.org

0, 16, 0, 596, 0, 24366, 0, 1001855, 0, 41171316, 0, 1691327788, 0, 69470653170, 0, 2853337539621, 0, 117191717993760, 0, 4813242705044572, 0, 197686734633818238, 0, 8119268451165592095, 0
Offset: 1

Views

Author

R. H. Hardin Jan 08 2013

Keywords

Comments

Column 3 of A221273

Examples

			Some solutions for n=4
..0..2..0....2..2..0....0..2..0....0..0..2....2..0..2....0..2..2....2..0..0
..0..2..0....2..0..0....2..2..0....2..2..2....2..2..0....2..2..0....2..0..2
..2..0..0....2..0..0....0..2..2....0..2..2....2..0..0....0..2..0....2..2..0
..2..2..2....0..2..2....0..2..0....0..0..0....0..2..0....0..2..0....0..0..2

A221272 Number of nX4 arrays of occupancy after each element moves to some king-move neighbor, with every occupancy equal to zero or two.

Original entry on oeis.org

1, 52, 596, 7252, 94659, 1250015, 16474842, 217194702, 2863102280, 37731750319, 497133557199, 6548899949298, 86261110576994, 1136131886838454
Offset: 1

Views

Author

R. H. Hardin Jan 08 2013

Keywords

Comments

Column 4 of A221273

Examples

			Some solutions for n=4
..0..2..2..0....0..2..0..2....0..2..2..2....0..2..2..0....0..2..2..2
..2..0..0..2....0..0..2..0....0..0..0..0....2..0..2..0....0..0..0..0
..0..2..2..0....2..2..0..2....2..0..2..0....0..2..0..2....0..2..2..2
..0..2..2..0....2..0..0..2....2..2..2..0....0..2..2..0....0..0..2..2
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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