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 1-10 of 11 results. Next

A221251 Number of nX4 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

4, 81, 2116, 58081, 1612900, 44903401, 1250753956, 34842328921, 970622980804, 27039303204489, 753252725702500, 20983889126032561, 584562920742585316, 16284579460194091201, 453650957002812576484, 12637673040690140943889
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Column 4 of A221255

Examples

			Some solutions for n=3
..0..1..2..1....1..1..1..0....1..2..0..0....0..2..2..2....0..1..1..1
..0..2..2..0....1..2..1..1....0..2..2..1....0..0..2..0....1..2..1..0
..0..1..2..1....0..1..2..1....2..1..1..0....0..1..2..1....1..1..2..1
		

Formula

Empirical: a(n) = 39*a(n-1) -356*a(n-2) +1365*a(n-3) -2739*a(n-4) +2904*a(n-5) -1683*a(n-6) +573*a(n-7) -116*a(n-8) +15*a(n-9) -a(n-10)

A221252 Number of nX5 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

8, 392, 22268, 1319409, 78633756, 4684821704, 278802326676, 16577412686597, 985111139474492, 58519095228020616, 3475483474225610814, 206383882956736627050, 12254681900155763390448, 727625190336114167472388
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Column 5 of A221255

Examples

			Some solutions for n=3
..1..1..1..2..0....0..1..0..2..0....0..2..1..1..0....0..1..1..2..0
..0..1..2..2..0....2..2..1..1..1....1..2..0..2..2....2..2..0..2..0
..1..2..0..1..1....1..1..1..2..0....1..0..1..2..0....0..0..2..2..1
		

A221253 Number of nX6 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

16, 2500, 488601, 103489929, 22466712321, 4919350997521, 1080371161000000, 237502965724417600, 52227958295629168900, 11486303574511411132081, 2526218624607638969433649, 555604441977129578423379025
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Column 6 of A221255

Examples

			Some solutions for n=3
..0..1..2..2..1..2....0..1..2..1..2..1....0..2..2..0..2..2....0..2..2..1..0..1
..1..1..1..1..1..0....0..2..1..1..2..0....0..2..1..1..2..1....0..1..1..1..2..0
..0..1..2..1..1..0....1..1..0..1..1..1....0..1..0..0..2..0....0..2..2..0..2..1
		

A221254 Number of nX7 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

32, 14112, 7356420, 4085800416, 2294073688498, 1286684357154700, 720107530988047980, 402418492897385719539, 224687866990231144007434, 125391176411370052357764435, 69957473447300728012460144928
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Column 7 of A221255

Examples

			Some solutions for n=3
..0..1..2..2..2..2..0....0..1..2..2..2..1..0....0..1..2..2..1..1..2
..0..2..1..2..0..1..0....0..2..1..0..1..2..2....0..1..2..2..1..2..0
..0..0..1..0..2..2..1....0..0..1..2..0..2..0....0..1..0..1..1..1..0
		

A221256 Number of 2 X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 4, 8, 81, 392, 2500, 14112, 83521, 484128, 2829124, 16473800, 96059601, 559785800, 3262922884, 19017180288, 110841719041, 646029804672, 3765346202500, 21946028005832, 127910874833361, 745519107896648
Offset: 1

Views

Author

R. H. Hardin, Jan 06 2013

Keywords

Comments

Row 2 of A221255.

Examples

			Some solutions for n=3:
  0 2 2   1 2 0   0 2 1   0 2 1   0 2 0   1 2 0   1 2 1
  0 2 0   0 2 1   0 2 1   1 2 0   1 2 1   1 2 0   0 2 0
		

Crossrefs

Cf. A221255.

Formula

Empirical: a(n) = 6*a(n-1) + 6*a(n-2) - 42*a(n-3) + 42*a(n-5) - 6*a(n-6) - 6*a(n-7) + a(n-8).
Empirical g.f.: x^2*(4 - 16*x + 9*x^2 + 26*x^3 - 2*x^4 - 6*x^5 + x^6) / ((1 - x)*(1 + x)*(1 - 6*x + x^2)*(1 + 2*x - x^2)*(1 - 2*x - x^2)). - Colin Barker, Aug 04 2018

A221257 Number of 3Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 16, 30, 2116, 22268, 488601, 7356420, 132273001, 2175160988, 37343243536, 627439570380, 10652755988736, 179923226827008, 3046558564618321, 51520912019433840, 871812703964410321, 14747896839403221578
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Row 3 of A221255

Examples

			Some solutions for n=3
..0..2..1....0..2..0....1..2..0....0..2..2....1..2..0....1..2..0....0..2..2
..0..2..0....1..2..0....0..2..1....0..2..0....0..2..0....1..2..1....0..2..1
..1..2..1....1..2..1....1..2..0....1..2..0....1..2..1....0..2..0....0..2..0
		

Formula

Empirical: a(n) = 21*a(n-1) +21*a(n-2) -1891*a(n-3) +4713*a(n-4) +31527*a(n-5) -98973*a(n-6) -92217*a(n-7) +299577*a(n-8) -27117*a(n-9) +103383*a(n-10) -393*a(n-11) +6211*a(n-12) +69*a(n-13) +69*a(n-14) +a(n-15) for n>18

A221258 Number of 4Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 64, 112, 58081, 1319409, 103489929, 4085800416, 226720727104, 10445351809532, 530909339760900, 25591483232781872, 1268920553028932644, 61970903049203536750, 3051063081822723807844, 149565983362653741790314
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Row 4 of A221255

Examples

			Some solutions for n=3
..1..2..1....0..2..0....1..2..0....0..2..1....1..2..0....0..2..1....0..2..0
..0..2..0....1..2..0....0..2..2....1..2..1....1..2..0....0..2..1....1..2..0
..0..2..1....2..2..0....0..2..0....0..2..1....0..2..2....1..2..0....1..2..1
..1..2..0....0..2..1....0..2..1....0..2..0....0..2..0....0..2..1....1..2..0
		

A221259 Number of 5Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 256, 418, 1612900, 78633756, 22466712321, 2294073688498, 399487764096100, 51031822108216122, 7730096571419434884, 1061888266253693915768, 154122481474602369093121, 21681358901642544133423968
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Row 5 of A221255

Examples

			Some solutions for n=3
..1..2..0....0..2..1....0..2..0....0..2..1....1..2..0....0..2..1....0..2..2
..0..2..2....0..2..1....1..2..0....1..2..1....1..2..1....0..2..0....0..2..1
..0..2..1....1..2..0....1..2..2....0..2..0....0..2..0....1..2..1....0..2..0
..0..2..0....0..2..0....0..2..0....0..2..1....0..2..1....1..2..1....0..2..2
..1..2..0....2..2..0....0..2..1....0..2..1....1..2..0....0..2..0....0..2..0
		

A221250 Number of n X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 4, 30, 58081, 78633756, 4919350997521, 720107530988047980, 2283974100099963226425600
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Diagonal of A221255

Examples

			Some solutions for n=3
..0..2..0....1..2..0....0..2..0....1..2..0....0..2..1....1..2..1....0..2..1
..2..2..0....1..2..0....1..2..0....0..2..1....1..2..0....0..2..0....1..2..1
..1..2..0....1..2..0....2..2..0....1..2..0....1..2..0....0..2..1....0..2..0
		

A221260 Number of 6Xn arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

Original entry on oeis.org

0, 1024, 1560, 44903401, 4684821704, 4919350997521, 1286684357154700, 711683286892712289, 249788326721013262468, 113635514869793774013025, 44202928096066452637659216
Offset: 1

Views

Author

R. H. Hardin Jan 06 2013

Keywords

Comments

Row 6 of A221255

Examples

			Some solutions for n=3
..0..2..2....1..2..0....1..2..0....1..2..0....0..2..1....0..2..1....0..2..1
..0..2..1....1..2..0....0..2..0....0..2..0....0..2..2....0..2..0....0..2..0
..0..2..1....0..2..0....1..2..2....2..2..0....0..2..1....2..2..0....1..2..0
..0..2..0....1..2..1....0..2..0....0..2..1....0..2..1....1..2..0....1..2..1
..0..2..0....1..2..0....0..2..1....0..2..1....0..2..0....0..2..0....0..2..0
..2..2..0....0..2..1....0..2..1....0..2..1....1..2..0....2..2..0....1..2..1
		
Showing 1-10 of 11 results. Next