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 1-4 of 4 results.

A185405 1/7 the number of n X 2 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

1, 13, 150, 1848, 22656, 278832, 3430776, 42221928, 519611520, 6394769688, 78699293256, 968538893952, 11919644165496, 146693048343528, 1805326578739200, 22217849450044248, 273431322619829256
Offset: 1

Views

Author

R. H. Hardin, Jan 26 2011

Keywords

Comments

Column 2 of A185409.

Examples

			Some solutions for 3 X 2 with a(1,1)=0:
..0..0....0..0....0..0....0..0....0..0....0..2....0..3....0..0....0..0....0..0
..2..5....2..2....5..1....6..6....2..2....0..2....0..3....0..6....0..1....6..5
..2..5....5..5....5..1....5..5....4..4....3..3....3..3....6..6....0..1....6..5

Links

Crossrefs

Cf. A185409.

Formula

Empirical: a(n) = 11*a(n-1) + 23*a(n-2) - 72*a(n-3) - 144*a(n-4) - 216*a(n-5).
Empirical g.f.: x*(1 + 2*x - 16*x^2 - 29*x^3 - 42*x^4) / (1 - 11*x - 23*x^2 + 72*x^3 + 144*x^4 + 216*x^5). - Colin Barker, Apr 15 2018

A185406 1/7 the number of nX3 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

1, 150, 5040, 279918, 12205368, 595974240, 27536905674, 1306753756812, 61210525548816, 2885367241303254, 135594323017300224, 6381618680273394960, 300126625465471449282, 14119903429577075460420, 664177642891735878467280
Offset: 1

Views

Author

R. H. Hardin Jan 26 2011

Keywords

Comments

Column 3 of A185409

Examples

			Some solutions for 5X3 with a(1,1)=0
..0..0..3....0..0..3....0..0..4....0..0..3....0..0..4....0..0..3....0..0..0
..0..2..3....0..0..3....0..0..4....0..1..3....0..0..4....0..0..3....0..1..0
..0..2..3....6..6..6....2..1..1....6..1..0....1..1..0....2..3..3....6..1..3
..5..2..4....4..4..2....2..1..3....6..3..0....2..1..0....2..0..6....6..6..3
..5..4..4....0..0..2....0..0..3....6..3..3....2..2..0....2..0..6....1..1..3

Links

Formula

Empirical: a(n)=27*a(n-1)+1101*a(n-2)-5388*a(n-3)-99699*a(n-4)+111696*a(n-5)+1303703*a(n-6)+1272279*a(n-7)-3839565*a(n-8)-46276758*a(n-9)+164100009*a(n-10)-201107172*a(n-11)-398097784*a(n-12)-1098237564*a(n-13)+6484304364*a(n-14)+1678354992*a(n-15)-32033066112*a(n-16)+111598281360*a(n-17)+135161638848*a(n-18)-357171462144*a(n-19)-773247897216*a(n-20)-848592391680*a(n-21)-825363302400*a(n-22)-1632586752000*a(n-23)

A185407 1/7 the number of nX4 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

7, 1848, 279918, 53808534, 9560464068, 1755419411964, 318289797234978, 58009184105051760, 10550717546713596858, 1920558372882730002666, 349484670721711744198032, 63604421284059206327321532
Offset: 1

Views

Author

R. H. Hardin Jan 26 2011

Keywords

Comments

Column 4 of A185409

Examples

			Some solutions for 3X4 with a(1,1)=0
..0..0..6..6....0..0..0..5....0..0..5..4....0..3..3..1....0..0..0..0
..3..1..1..1....0..2..3..5....4..3..5..4....0..3..0..1....3..3..3..2
..3..3..4..4....0..2..3..3....4..3..3..3....0..3..0..0....3..6..6..2

Links

A185408 1/7 the number of nX5 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Original entry on oeis.org

13, 22656, 12205368, 9560464068, 6409594156632
Offset: 1

Views

Author

R. H. Hardin Jan 26 2011

Keywords

Comments

Column 5 of A185409

Examples

			Some solutions for 3X5 with a(1,1)=0
..0..0..1..0..1....0..0..0..5..5....0..0..0..6..6....0..0..2..2..4
..0..0..1..0..1....0..1..1..3..0....0..1..1..4..4....0..1..1..6..4
..4..4..2..2..2....0..0..0..3..0....3..3..3..4..4....3..3..1..6..4
Showing 1-4 of 4 results.

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