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.

A198906 T(n,k) = number of n X k 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.

Original entry on oeis.org

1, 1, 1, 2, 4, 2, 5, 33, 33, 5, 15, 380, 1211, 380, 15, 51, 4801, 50384, 50384, 4801, 51, 187, 62004, 2125425, 6907736, 2125425, 62004, 187, 715, 804833, 89793204, 948656912, 948656912, 89793204, 804833, 715, 2795, 10459180, 3794115705
Offset: 1

Views

Author

R. H. Hardin, Oct 31 2011

Keywords

Comments

Number of colorings of the grid graph P_n X P_k using a maximum of 5 colors up to permutation of the colors. - Andrew Howroyd, Jun 26 2017

Examples

			Table starts
.....1..........1...............2....................5
.....1..........4..............33..................380
.....2.........33............1211................50384
.....5........380...........50384..............6907736
....15.......4801.........2125425............948656912
....51......62004........89793204.........130292546801
...187.....804833......3794115705.......17895005957823
...715...10459180....160319061892.....2457786852894234
..2795..135958401...6774239755817...337564362706067534
.11051.1767426404.286243775060868.46362726246946052884
...
Some solutions with values 0 to 4 for n=6, k=4:
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0
..0..1..0..2....0..1..0..2....0..1..0..2....0..1..0..2....0..1..0..2
..2..0..2..0....2..0..3..0....2..0..2..3....2..0..1..0....2..0..1..3
..3..2..1..4....0..1..0..4....0..4..0..2....3..2..4..3....0..3..4..2
..2..4..2..1....2..4..3..1....1..3..1..4....1..0..1..2....4..0..1..4
		

Crossrefs

Columns 1-7 are A007581(n-2), A198900, A198901, A198902, A198903, A198904, A198905.
Main diagonal is A198899.
Cf. A207997 (3 colorings), A198715 (4 colorings), A222144 (labeled 5 colorings), A198982 (6 colorings), A198723 (7 colorings), A198914 (8 colorings), A207868 (unlimited).

A214141 T(n,k)=Number of 0..4 colorings of an nx(k+1) array circular in the k+1 direction with new values 0..4 introduced in row major order.

Original entry on oeis.org

1, 1, 4, 4, 17, 33, 11, 257, 514, 380, 40, 3074, 28278, 16388, 4801, 147, 40434, 1101051, 3221873, 524296, 62004, 568, 522515, 47730973, 396246659, 367793014, 16777232, 804833, 2227, 6800539, 2000093424, 56449101747, 142612676441, 41989913081
Offset: 1

Views

Author

R. H. Hardin Jul 05 2012

Keywords

Comments

Table starts
....1......1.........4...........11.............40...............147
....4.....17.......257.........3074..........40434............522515
...33....514.....28278......1101051.......47730973........2000093424
..380..16388...3221873....396246659....56449101747.....7658621867351
.4801.524296.367793014.142612676441.66761857485037.29325981412599886

Examples

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

Crossrefs

Column 1 is A198900

Formula

Empirical for column k:
k=1: a(n) = 17*a(n-1) -55*a(n-2) +39*a(n-3)
k=2: a(n) = 34*a(n-1) -64*a(n-2)
k=3: a(n) = 129*a(n-1) -1759*a(n-2) +7575*a(n-3) -9064*a(n-4) +3120*a(n-5)
k=4: a(n) = 373*a(n-1) -4754*a(n-2) +15312*a(n-3)
k=5: (order 10)
k=6: (order 9)
Empirical for row n:
n=1: a(k)=6*a(k-1)-7*a(k-2)-6*a(k-3)+8*a(k-4)
n=2: a(k)=10*a(k-1)+50*a(k-2)-116*a(k-3)-361*a(k-4)+106*a(k-5)+312*a(k-6)
n=3: (order 15)
n=4: (order 37)

A214166 T(n,k)=Number of 0..5 colorings of an nx(k+1) array circular in the k+1 direction with new values 0..5 introduced in row major order.

Original entry on oeis.org

1, 1, 4, 4, 18, 34, 11, 337, 902, 481, 41, 5994, 88261, 60320, 8731, 161, 121778, 7386816, 27240856, 4242606, 174454, 694, 2518082, 655418810, 9601970064, 8548472292, 300785428, 3603244, 3151, 52655411, 57661437162, 3598372134742
Offset: 1

Views

Author

R. H. Hardin Jul 05 2012

Keywords

Comments

Table starts
....1.......1..........4.............11................41..................161
....4......18........337...........5994............121778..............2518082
...34.....902......88261........7386816.........655418810..........57661437162
..481...60320...27240856.....9601970064.....3598372134742.....1329144373535118
.8731.4242606.8548472292.12515731371696.19767477649307133.30641183868207736684

Examples

			Some solutions for n=4 k=1
..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1
..1..2....1..2....1..2....1..2....1..2....1..0....1..0....1..0....2..3....2..3
..3..4....0..1....3..0....2..0....0..3....2..1....2..3....2..3....3..1....0..1
..5..3....1..0....0..4....0..2....1..2....0..2....0..4....1..0....4..2....1..3
		

Crossrefs

Column 1 is A198900

Formula

Empirical for column k:
k=1: a(n) = 32*a(n-1) -262*a(n-2) +672*a(n-3) -441*a(n-4)
k=2: a(n) = 84*a(n-1) -945*a(n-2) +1562*a(n-3)
k=3: a(n) = 370*a(n-1) -18411*a(n-2) +297448*a(n-3) -1839799*a(n-4) +4424682*a(n-5) -4113757*a(n-6) +1249468*a(n-7)
k=4: a(n) = 1402*a(n-1) -130492*a(n-2) +2979072*a(n-3) -15573492*a(n-4) +12571416*a(n-5)
k=5: (order 15)
Empirical for row n:
n=1: a(k)=10*a(k-1)-30*a(k-2)+20*a(k-3)+31*a(k-4)-30*a(k-5)
n=2: a(k)=21*a(k-1)+49*a(k-2)-959*a(k-3)-1869*a(k-4)+7679*a(k-5)+15051*a(k-6)-6741*a(k-7)-13230*a(k-8)
n=3: (order 22)
n=4: (order 60)

A206389 T(n,k)=Number of nXk 0..6 arrays with no element equal to another within a city block distance of two, and new values 0..6 introduced in row major order.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 4, 4, 2, 5, 33, 55, 33, 5, 15, 380, 1368, 1368, 380, 15, 52, 4801, 34442, 67716, 34442, 4801, 52, 202, 62004, 868994, 3328979, 3328979, 868994, 62004, 202, 855, 804833, 21916090, 164270604, 319902496, 164270604, 21916090, 804833, 855
Offset: 1

Views

Author

R. H. Hardin Feb 07 2012

Keywords

Comments

Table starts
...1......1.........1..........2...........5..........15............52
...1......1.........4.........33.........380........4801.........62004
...1......4........55.......1368.......34442......868994......21916090
...2.....33......1368......67716.....3328979...164270604....8094257014
...5....380.....34442....3328979...319902496.30809397399.2965468376203
..15...4801....868994..164270604.30809397399
..52..62004..21916090.8094257014
.202.804833.552801398

Examples

			Some solutions for n=4 k=3
..0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..2..3..0....2..3..0....3..4..0....2..3..4....2..3..4....3..4..5....2..3..4
..4..5..1....4..5..6....1..2..5....4..5..1....1..5..6....5..2..1....4..5..6
..6..2..4....6..2..1....6..0..1....6..0..2....6..2..0....1..6..4....6..0..1
		

Crossrefs

Column 1 is A056272(n-2)
Column 2 is A198900(n-1)
Showing 1-4 of 4 results.