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 1-7 of 7 results.

A197883 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

0, 4, 3, 14, 18, 43, 78, 154, 305, 572, 1178, 2185, 4440, 8408, 16795, 32212, 63608, 123295, 241494, 470486, 918795, 1793434, 3497978, 6831997, 13324168, 26019470, 50755921, 99095168, 193344576, 377408195, 736481712, 1437442548, 2805273219
Offset: 1

Views

Author

R. H. Hardin, Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's.
Column 2 of A197889.

Examples

			Some solutions for n=4:
..2..1....2..1....1..2....1..2....2..1....1..2....0..1....2..1....0..1....1..2
..1..3....1..3....3..1....3..1....1..0....0..1....1..2....1..0....1..2....0..1
..3..1....0..1....1..3....1..0....1..2....2..1....1..2....3..1....1..0....1..0
..1..2....1..2....2..1....2..1....0..1....1..0....0..1....1..2....2..1....2..1
		

Crossrefs

Cf. A197889.

Formula

Empirical: a(n) = 3*a(n-2) +2*a(n-3) +a(n-4) -3*a(n-5) -4*a(n-6) +7*a(n-7) -5*a(n-9).
Empirical g.f.: x^2*(4 + 3*x + 2*x^2 + x^3 - 9*x^4 + 5*x^5 - 7*x^7) / ((1 - x)*(1 + x - 2*x^2 - 4*x^3 - 5*x^4 - 2*x^5 + 2*x^6 - 5*x^7 - 5*x^8)). - Colin Barker, May 14 2018

A197884 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

1, 3, 6, 47, 77, 196, 529, 1637, 4235, 11211, 30271, 83254, 225148, 606579, 1638498, 4440639, 12016918, 32485381, 87846790, 237662631, 642926239, 1738933011, 4703362637, 12722244082, 34413103568, 93083202626, 251777401480
Offset: 1

Views

Author

R. H. Hardin, Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's.

Examples

			Some solutions for n=4
..1..2..0....1..1..0....1..1..2....0..1..1....2..1..0....0..1..2....0..1..2
..0..1..1....2..2..1....2..3..1....1..2..2....1..1..2....1..0..1....1..4..1
..1..1..2....1..0..1....1..1..3....1..3..1....1..4..1....2..2..1....2..1..1
..2..1..0....0..1..2....0..2..1....2..1..0....2..1..0....1..1..0....0..1..2
		

Crossrefs

Column 3 of A197889.

Formula

Empirical: a(n) = a(n-1) +a(n-2) +4*a(n-3) +12*a(n-4) +7*a(n-5) +21*a(n-6) -22*a(n-7) -6*a(n-8) -64*a(n-9) -136*a(n-10) +16*a(n-11) +112*a(n-12) +621*a(n-13) +473*a(n-14) +396*a(n-15) -294*a(n-16) -1044*a(n-17) -744*a(n-18) -475*a(n-19) +1462*a(n-20) +156*a(n-21) -1601*a(n-22) -627*a(n-23) -2504*a(n-24) -1566*a(n-25) +468*a(n-26) -518*a(n-27) +384*a(n-28) +444*a(n-29) +208*a(n-30) +400*a(n-31) +96*a(n-32).
Empirical formula verified: see link. - Robert Israel, Aug 24 2018

A197885 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

2, 14, 47, 155, 835, 2263, 10827, 38938, 157178, 654028, 2607334, 10482745, 41930639, 169374587, 686689100, 2793219587, 11244612740, 45359859580, 183328706973, 742423862981, 3008747408411, 12158966386525, 49114866456717
Offset: 1

Views

Author

R. H. Hardin Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Column 4 of A197889

Examples

			Some solutions containing all values 0 to 4 for n=5
..2..1..0..1....2..1..1..2....2..1..1..2....0..1..2..1....0..1..1..2
..1..3..1..2....1..4..1..1....1..1..4..1....2..1..3..1....1..2..0..1
..0..2..1..0....0..1..2..0....0..2..1..0....1..4..1..2....0..2..1..3
..1..1..4..1....2..1..0..1....1..3..1..2....0..1..1..0....1..1..4..1
..2..1..1..2....1..3..1..2....2..1..3..1....1..2..2..1....2..1..1..2
		

A197886 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

1, 18, 77, 835, 2730, 17890, 92843, 567991, 3000116, 17111462, 94740977, 537643352, 2995145891, 16728999681, 93489922434, 524952952537, 2940191924830, 16425787144594, 91861015115420, 514650900540840, 2882700958009902
Offset: 1

Views

Author

R. H. Hardin Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Column 5 of A197889

Examples

			Some solutions containing all values 0 to 4 for n=4
..2..1..0..1..2....1..2..2..1..0....1..2..2..1..1....2..1..0..1..2
..1..0..2..1..1....0..1..1..1..2....0..1..1..0..2....1..0..2..1..1
..1..3..1..4..1....2..1..4..1..1....2..1..4..1..1....3..1..1..4..1
..2..1..0..1..2....1..3..1..2..0....1..3..1..2..0....1..2..0..1..2
		

A197887 Number of nX6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

1, 43, 196, 2263, 17890, 129294, 1134527, 9389938, 74334188, 612587633, 4957017898, 40458420396, 328259829544, 2682720603080, 21878875862100, 178129467799644, 1450139820586951, 11818051611475707, 96281373184386270
Offset: 1

Views

Author

R. H. Hardin Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Column 6 of A197889

Examples

			Some solutions containing all values 0 to 4 for n=4
..1..2..2..1..0..1....0..1..2..2..1..0....1..2..0..1..1..0....1..2..2..1..0..1
..3..1..1..4..1..2....2..1..1..1..3..1....3..1..1..2..2..1....3..1..1..4..1..2
..1..3..3..1..1..0....1..4..1..1..0..2....1..4..1..2..0..1....1..3..3..1..1..2
..2..1..1..2..2..1....0..1..2..2..1..1....2..1..3..1..1..2....2..1..1..2..0..1
		

A197888 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

3, 78, 529, 10827, 92843, 1134527, 13253562, 145351090, 1728849664, 19259087568, 227927217325, 2573394846501, 29961925871053, 341720932452731, 3939440439598059, 45203853693284547, 520558824415292051
Offset: 1

Views

Author

R. H. Hardin Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Column 7 of A197889

Examples

			Some solutions containing all values 0 to 4 for n=4
..1..0..2..1..0..1..2....0..1..2..2..1..3..1....1..2..2..1..0..1..2
..2..1..1..0..2..1..1....1..3..1..1..4..1..2....0..1..1..3..2..1..1
..2..1..4..1..1..0..1....2..2..1..1..1..1..2....2..1..0..1..1..4..1
..1..3..1..2..0..1..2....1..1..1..2..2..1..1....1..0..1..2..0..1..2
		

A197882 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.

Original entry on oeis.org

1, 4, 6, 155, 2730, 129294, 13253562, 2512321052
Offset: 1

Views

Author

R. H. Hardin Oct 19 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
Diagonal of A197889

Examples

			Some solutions containing all values 0 to 4 for n=4
..1..0..2..1....1..0..2..1....1..3..1..2....2..1..3..1....1..3..1..2
..2..1..1..3....2..1..1..3....2..1..4..1....1..4..1..2....2..1..4..1
..2..1..4..1....2..1..4..1....2..1..1..3....3..1..1..2....0..1..1..0
..1..3..1..2....1..0..1..2....1..0..2..1....1..2..0..1....1..2..2..1
		
Showing 1-7 of 7 results.