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.

A199641 Number of n X 2 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

1, 3, 13, 60, 288, 1384, 6628, 31772, 152304, 730036, 3499340, 16773680, 80402532, 385399644, 1847365808, 8855120468, 42445929772, 203459338800, 975257291396, 4674775757500, 22407962058928, 107409807372276, 514855687878924
Offset: 1

Views

Author

R. H. Hardin, Nov 08 2011

Keywords

Comments

Column 2 of A199647.

Examples

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

Crossrefs

Cf. A199647.

Formula

Empirical: a(n) = 3*a(n-1) +7*a(n-2) +8*a(n-3) -8*a(n-5) for n>7.
Empirical g.f.: x*(1 - 3*x^2 - 8*x^3 - 7*x^4 + 4*x^5 + 4*x^6) / (1 - 3*x - 7*x^2 - 8*x^3 + 8*x^5). - Colin Barker, May 16 2018

A199642 Number of nX3 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

1, 13, 112, 1265, 12748, 134748, 1396083, 14584050, 151837464, 1582988477, 16494233432, 171904221068, 1791430664487, 18669394073270, 194560012081184, 2027588187779377, 21130256645906468, 220206564513115724
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Column 3 of A199647

Examples

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

Formula

Empirical: a(n) = 7*a(n-1) +41*a(n-2) -44*a(n-3) -111*a(n-4) -140*a(n-5) +291*a(n-6) -225*a(n-7) +511*a(n-8) +2150*a(n-9) -3007*a(n-10) -6248*a(n-11) -624*a(n-12) +19900*a(n-13) -14308*a(n-14) +15248*a(n-15) -13312*a(n-16) -1648*a(n-17) +21440*a(n-18) -5632*a(n-19) -3968*a(n-20) +5632*a(n-21) -14336*a(n-22) -8192*a(n-23) for n>24

A199643 Number of nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

2, 60, 1265, 29229, 658770, 15066222, 342328663, 7797114144, 177447181083, 4039488090307, 91947444344704, 2092999963213610, 47642308975551650, 1084472533833020100, 24685590900071146822, 561912613968766782369
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Column 4 of A199647

Examples

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

A199644 Number of nX5 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

3, 288, 12748, 658770, 32177372, 1614250077, 80053957248, 3988024796446, 198328767139736, 9869645990489747, 491026123739354858, 24431608808618462704, 1215575822472077464282, 60480991464785183388557
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Column 5 of A199647

Examples

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

A199645 Number of nX6 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

6, 1384, 134748, 15066222, 1614250077, 176701683386, 19161971644783, 2085499380111100, 226676302441401393, 24649864713781053665, 2680046304287719376722, 291407720701800854792287
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Column 6 of A199647

Examples

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

A199640 Number of n X n 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

0, 3, 112, 29229, 32177372, 176701683386, 4539946639286136
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Diagonal of A199647

Examples

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

A199646 Number of nX7 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Original entry on oeis.org

11, 6628, 1396083, 342328663, 80053957248, 19161971644783, 4539946639286136, 1079929763429897946, 256503858825070983388
Offset: 1

Views

Author

R. H. Hardin Nov 08 2011

Keywords

Comments

Column 7 of A199647

Examples

			Some solutions for n=3
..0..0..1..2..2..0..2....0..1..1..2..0..1..1....0..0..1..1..0..0..0
..0..0..1..2..2..0..2....0..0..0..2..0..2..2....0..0..2..2..0..2..0
..1..1..0..0..0..1..1....1..1..1..1..1..1..2....1..1..1..1..1..2..0
		
Showing 1-7 of 7 results.