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 1-5 of 5 results.

A185535 1/6 the number of n X 2 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

1, 11, 110, 1155, 12105, 127190, 1336205, 14039455, 147510990, 1549891055, 16284627805, 171101820790, 1797758782905, 18888967243155, 198465493076590, 2085267630701755, 21909809227375505, 230205338311698390
Offset: 1

Views

Author

R. H. Hardin, Jan 30 2011

Keywords

Comments

Column 2 of A185540.

Examples

			Some solutions for 3 X 2 with a(1,1)=0:
..0..4....0..0....0..0....0..0....0..0....0..0....0..3....0..5....0..0....0..5
..0..4....5..1....0..5....1..1....1..3....0..2....0..3....0..5....2..0....0..5
..0..4....5..1....0..5....3..3....1..3....2..2....3..3....3..3....2..0....5..5
		

Crossrefs

Cf. A185540.

Formula

Empirical: a(n) = 9*a(n-1) + 19*a(n-2) - 25*a(n-3) - 75*a(n-4) - 125*a(n-5).
Empirical g.f.: x*(1 + 2*x - 8*x^2 - 19*x^3 - 30*x^4) / (1 - 9*x - 19*x^2 + 25*x^3 + 75*x^4 + 125*x^5). - Colin Barker, Apr 16 2018

A185536 1/6 the number of nX3 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

1, 110, 2990, 127570, 4403225, 167398110, 6079401960, 225574291125, 8285469213945, 305786452982260, 11260066599241195, 415073544779136460, 15292958690004125565, 563586551260018728505, 20767361004817999220125
Offset: 1

Views

Author

R. H. Hardin Jan 30 2011

Keywords

Comments

Column 3 of A185540

Examples

			Some solutions for 5X3 with a(1,1)=0
..0..0..0....0..0..0....0..0..3....0..0..3....0..0..0....0..0..0....0..3..3
..0..3..3....0..3..3....0..0..3....0..3..3....0..3..3....0..3..3....0..0..0
..4..0..0....4..1..3....3..3..1....1..0..0....0..2..2....2..2..3....5..2..0
..4..4..4....4..1..0....5..5..1....1..1..2....3..4..2....2..4..0....5..2..2
..5..5..4....0..0..0....4..4..4....5..5..2....3..4..4....2..4..0....5..5..5
		

Formula

Empirical: a(n)=22*a(n-1)+638*a(n-2)-2567*a(n-3)-29583*a(n-4)+27088*a(n-5)+209637*a(n-6)+620796*a(n-7)-1634411*a(n-8)-4083145*a(n-9)+17086070*a(n-10)-21827225*a(n-11)-42404829*a(n-12)-73933685*a(n-13)+687497360*a(n-14)-669370750*a(n-15)-1844490625*a(n-16)+8145764375*a(n-17)+6297734375*a(n-18)-14443984375*a(n-19)-34831953125*a(n-20)-42570312500*a(n-21)-47656250000*a(n-22)-78125000000*a(n-23)

A185537 1/6 the number of nX4 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

6, 1155, 127570, 17526450, 2241330570, 295044602325, 38418831900875, 5024252800116630, 655951718326130130, 85695581922306489845, 11192649881286988768850, 1462013677990229903804335
Offset: 1

Views

Author

R. H. Hardin Jan 30 2011

Keywords

Comments

Column 4 of A185540

Examples

			Some solutions for 3X4 with a(1,1)=0
..0..5..5..4....0..2..5..5....0..0..2..4....0..1..2..2....0..0..0..2
..0..1..5..4....0..2..3..5....1..3..2..4....0..1..0..4....3..2..2..2
..1..1..3..3....2..2..3..3....1..3..4..4....5..5..0..4....3..5..5..5
		

A185538 1/6 the number of nX5 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

11, 12105, 4403225, 2241330570, 994633804270, 468362874353295
Offset: 1

Views

Author

R. H. Hardin Jan 30 2011

Keywords

Comments

Column 5 of A185540

Examples

			Some solutions for 3X5 with a(1,1)=0
..0..0..0..4..4....0..0..3..3..5....0..0..0..3..4....0..0..0..0..1
..0..3..3..2..4....3..3..4..3..5....0..3..1..3..4....0..3..2..1..1
..0..0..0..2..2....0..0..4..4..5....0..3..1..5..5....0..3..2..5..5
		

A185539 1/6 the number of nX6 0..5 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

41, 127190, 167398110, 295044602325, 468362874353295
Offset: 1

Views

Author

R. H. Hardin Jan 30 2011

Keywords

Comments

Column 6 of A185540

Examples

			Some solutions for 3X6 with a(1,1)=0
..0..0..3..4..2..2....0..0..2..2..2..4....0..0..3..1..0..0....0..0..3..5..3..3
..0..3..3..4..4..2....0..3..3..1..2..4....0..3..3..1..3..4....0..3..3..5..2..3
..0..0..0..2..2..2....0..0..0..1..2..2....0..0..0..3..3..4....0..0..0..5..2..2
		
Showing 1-5 of 5 results.