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.

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A264285 T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change 0,0 0,1 1,0 or -1,-2.

Original entry on oeis.org

1, 4, 1, 8, 10, 1, 16, 32, 26, 1, 33, 102, 132, 69, 1, 69, 360, 675, 556, 181, 1, 145, 1228, 4189, 4484, 2324, 476, 1, 300, 4156, 23852, 47492, 29742, 9724, 1252, 1, 624, 14148, 134432, 448821, 537057, 197283, 40692, 3292, 1, 1300, 48188, 768664, 4227024
Offset: 1

Views

Author

R. H. Hardin, Nov 10 2015

Keywords

Comments

Table starts
.1.....4.......8........16..........33.............69..............145
.1....10......32.......102.........360...........1228.............4156
.1....26.....132.......675........4189..........23852...........134432
.1....69.....556......4484.......47492.........448821..........4227024
.1...181....2324.....29742......537057........8405669........131452948
.1...476....9724....197283.....6080234......157344756.......4076914388
.1..1252...40692...1308629....68815948.....2943284092.....126311779972
.1..3292..170268...8680430...778858184....55051679668....3911932445892
.1..8657..712468..57579243..8815152033..1029653214581..121136137544916
.1.22765.2981244.381936079.99770013733.19257696830753.3750881659750212

Examples

			Some solutions for n=4 k=4
..7..0..9..2..3....7..1..9..2..4....0..1..9..2..3....0..1..9..2..3
.12..1..6..8..4....0.13..6..3..8....5.13..6..7..4...12..5.14..7..4
..5.11.19.13.14....5.10.11.12.14...10.11.12..8.14...10..6.11..8.13
.10.23.16.17.18...22.15.16.18.19...22.15.24.17.18...15.23.16.17.19
.15.20.21.22.24...20.21.17.23.24...20.16.21.23.19...20.21.22.18.24
		

Crossrefs

Column 2 is A099234(n+1).
Row 1 is A264166.

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = a(n-1) +3*a(n-2) +3*a(n-3) +a(n-4)
k=3: a(n) = 3*a(n-1) +4*a(n-2) +4*a(n-3)
k=4: a(n) = 7*a(n-1) -2*a(n-2) -2*a(n-3) -6*a(n-4) +a(n-5) +3*a(n-6)
k=5: [order 28]
k=6: [order 36]
k=7: [order 34]
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2) +2*a(n-3) +a(n-4) +a(n-5) -a(n-6)
n=2: a(n) = a(n-1) +4*a(n-2) +10*a(n-3) +12*a(n-4) +8*a(n-5) for n>7
n=3: [order 56]

A297224 T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.

Original entry on oeis.org

1, 2, 1, 3, 4, 1, 4, 8, 9, 1, 6, 16, 24, 19, 1, 9, 33, 57, 68, 41, 1, 13, 69, 182, 207, 196, 88, 1, 19, 145, 535, 997, 751, 564, 189, 1, 28, 300, 1513, 4210, 5570, 2720, 1620, 406, 1, 41, 624, 4415, 16658, 33158, 30946, 9861, 4660, 872, 1, 60, 1300, 12832, 68769, 178469
Offset: 1

Views

Author

R. H. Hardin, Dec 27 2017

Keywords

Comments

Table starts
.1...2.....3......4.......6.........9.........13..........19............28
.1...4.....8.....16......33........69........145.........300...........624
.1...9....24.....57.....182.......535.......1513........4415.........12832
.1..19....68....207.....997......4210......16658.......68769........284867
.1..41...196....751....5570.....33158.....178469.....1051514.......6152761
.1..88...564...2720...30946....261939....1918732....16176806.....134671502
.1.189..1620...9861..171851...2063378...20599895...248421807....2936448567
.1.406..4660..35741..955316..16277793..221333623..3819208252...64142817874
.1.872.13396.129540.5308160.128351805.2377449633.58680928294.1400212345305

Examples

			Some solutions for n=5 k=4
..0..0..0..0. .0..0..1..1. .0..0..0..0. .0..0..0..0. .0..1..1..0
..0..0..1..0. .0..0..0..0. .0..1..0..0. .0..1..0..0. .0..0..0..0
..0..1..0..0. .0..1..0..0. .1..0..0..0. .1..0..0..0. .0..1..0..0
..0..1..1..0. .1..0..0..1. .0..1..1..0. .0..0..1..1. .1..0..0..0
..0..0..0..0. .0..0..1..0. .0..0..1..1. .0..0..0..0. .0..1..1..0
		

Crossrefs

Column 2 is A078039.
Row 1 is A000930(n+1).
Row 2 is A264166.

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = a(n-1) +2*a(n-2) +a(n-3)
k=3: a(n) = a(n-1) +4*a(n-2) +4*a(n-3)
k=4: a(n) = a(n-1) +6*a(n-2) +11*a(n-3) +6*a(n-4) +a(n-5)
k=5: [order 9]
k=6: [order 11] for n>13
k=7: [order 16] for n>21
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-3)
n=2: a(n) = a(n-1) +a(n-2) +2*a(n-3) +a(n-4) +a(n-5) -a(n-6)
n=3: [order 13]
n=4: [order 27]
n=5: [order 60]
Showing 1-2 of 2 results.