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 1-6 of 6 results.

A181219 Number of nX3 binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

7, 49, 230, 1209, 6475, 34020, 179097, 944514, 4978956, 26241679, 138316703, 729070278, 3842881010, 20255521442, 106765644778, 562755120940, 2966245831625, 15634892911279, 82410528967137, 434380653636920
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Column 3 of A181224

Examples

			Some avoided solutions for 4X3
..1..0..0....1..1..0....1..0..0....1..0..0....0..0..1....0..0..0....0..0..1
..0..1..0....0..1..0....0..0..1....0..1..0....0..1..0....0..0..0....0..1..0
..0..0..1....0..0..1....0..1..0....0..0..1....1..0..1....0..0..1....1..0..0
..0..1..0....0..0..0....1..0..0....1..0..0....0..0..0....1..1..1....0..0..1
		

Formula

Empirical: a(n)=2*a(n-1)+8*a(n-2)+38*a(n-3)+51*a(n-4)+41*a(n-5)-48*a(n-6)-88*a(n-7)-4*a(n-8)-8*a(n-9)-15*a(n-10)+14*a(n-11)-7*a(n-12)+a(n-13)-2*a(n-14)

A181220 Number of n X 4 binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

13, 169, 1209, 10732, 97764, 845531, 7426986, 65480503, 574725752, 5050028956, 44391722285, 390072820213, 3427866363455, 30124436697657, 264728435711181, 2326400950974628, 20444198985083330, 179661312288590309
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Column 4 of A181224.

Examples

			Some avoided solutions for 3 X 4
..0..1..0..1....1..0..0..0....0..0..1..0....1..0..0..0....0..0..0..1
..0..0..1..0....1..0..0..0....0..0..1..1....0..1..0..0....0..1..0..1
..0..1..0..0....1..1..0..0....0..0..1..0....1..0..1..0....0..0..0..1
		

Crossrefs

Cf. A181224.

Formula

Empirical: a(n)=4*a(n-1)+27*a(n-2)+150*a(n-3)-59*a(n-4)-656*a(n-5)-2090*a(n-6)+4600*a(n-7)+558*a(n-8)-6222*a(n-9)+6935*a(n-10)-36512*a(n-11)+93343*a(n-12)-70961*a(n-13)+82681*a(n-14)-47047*a(n-15)-247244*a(n-16)+404537*a(n-17)-466677*a(n-18)+482071*a(n-19)-352513*a(n-20)+295888*a(n-21)-133016*a(n-22)+13672*a(n-23)-34436*a(n-24)+7664*a(n-25)+7816*a(n-26)+108*a(n-27)-620*a(n-28)-1024*a(n-29)+144*a(n-30)+32*a(n-31)+48*a(n-32).

A181221 Number of nX5 binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

24, 576, 6475, 97764, 1495392, 21513936, 316896477, 4672517426, 68571093673, 1008146803248, 14823077688569, 217869625616208, 3202690847200999, 47079980407589036, 692062815855417554, 10173239318638447266
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Column 5 of A181224

Examples

			Some avoided solutions for 3X5
..0..1..0..0..0....0..1..0..0..0....0..0..0..0..0....0..0..0..0..1
..0..0..1..0..0....0..1..0..0..0....0..0..0..0..0....0..0..0..1..0
..1..0..0..1..0....0..1..0..1..0....1..1..1..1..0....1..0..1..0..0
		

A181222 Number of nX6 binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

44, 1936, 34020, 845531, 21513936, 507962194, 12297765846, 298705742479, 7214603356059, 174532135006271, 4223718879095262, 102172834596986892, 2471821868183143126, 59801751244062857757, 1446764589780206695039
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Column 6 of A181224

Examples

			Some avoided solutions for 3X6
..0..0..0..1..1..0....0..0..0..0..1..0....1..0..1..1..1..0....0..1..0..0..0..0
..0..0..1..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0....0..0..1..1..0..0
..0..1..0..0..0..0....0..0..1..1..1..0....0..0..0..0..0..0....0..0..0..1..0..0
		

A181223 Number of nX7 binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

81, 6561, 179097, 7426986, 316896477, 12297765846, 493466099722, 19886730240632, 794878208506289, 31852650059853831, 1277093175893680596, 51166967011661264756, 2050407503529684003122, 82170493913101130433607
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Column 7 of A181224

Examples

			Some avoided solutions for 3X7
..1..0..0..0..0..1..0....0..0..0..0..0..0..0....0..1..0..1..0..0..0
..1..0..0..0..0..0..0....1..1..1..0..0..0..0....0..0..0..0..1..0..0
..1..0..0..0..0..0..0....1..0..0..0..0..0..0....0..0..0..0..0..1..0
		

A181218 Number of n X n binary matrices with no three 1's adjacent in a line horizontally, vertically, diagonally or antidiagonally.

Original entry on oeis.org

2, 16, 230, 10732, 1495392, 507962194, 493466099722, 1328921689649459, 9633695407844528952, 192630734231370260714836, 10572973250296811381776668634
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

Diagonal of A181224

Examples

			Some avoided solutions for 3X3
..1..1..1....1..0..0....0..0..1....1..1..1....1..0..0....1..1..0....1..0..0
..0..0..0....0..1..1....0..1..0....0..0..1....0..0..0....0..1..0....1..0..0
..0..0..1....0..0..1....1..0..1....0..0..0....1..1..1....0..0..1....1..1..0
		
Showing 1-6 of 6 results.