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 1-10 of 10 results.

A207068 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 8, 14, 81, 102, 64, 10, 21, 196, 288, 216, 100, 12, 31, 441, 896, 720, 390, 144, 14, 46, 961, 2499, 2688, 1485, 636, 196, 16, 68, 2116, 6634, 8799, 6398, 2709, 966, 256, 18, 100, 4624, 17848, 27063, 23856, 13132, 4536, 1392, 324, 20, 147
Offset: 1

Views

Author

R. H. Hardin Feb 14 2012

Keywords

Comments

Table starts
..2...4....6....9....14.....21.....31......46.......68......100.......147
..4..16...36...81...196....441....961....2116.....4624....10000.....21609
..6..36..102..288...896...2499...6634...17848....47192...122200....315315
..8..64..216..720..2688...8799..27063...84502...257584...762900...2246895
.10.100..390.1485..6398..23856..82739..291364...997288..3297100..10818024
.12.144..636.2709.13132..54684.210118..818892..3093184.11234900..40417797
.14.196..966.4536.24304.111426.468348.1992996..8204200.32364700.126207438
.16.256.1392.7128.41664.208026.947298.4356936.19360144.82226100.344542569

Examples

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

Crossrefs

Column 2 is A016742
Column 3 is A086113
Row 1 is A038718(n+2)

Formula

Empirical for column k:
k=1: a(n) = 2*n
k=2: a(n) = 4*n^2
k=3: a(n) = 2*n^3 + 6*n^2 - 2*n
k=4: a(n) = (3/4)*n^4 + (15/2)*n^3 + (15/4)*n^2 - 3*n
k=5: a(n) = (7/30)*n^5 + 7*n^4 + (21/2)*n^3 - (56/15)*n
k=6: a(n) = (7/120)*n^6 + (147/40)*n^5 + (49/3)*n^4 + (91/8)*n^3 - (707/120)*n^2 - (91/20)*n
k=7: a(n) = (31/2520)*n^7 + (62/45)*n^6 + (4867/360)*n^5 + (2015/72)*n^4 + (1271/180)*n^3 - (4991/360)*n^2 - (713/140)*n

A207254 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 1 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 8, 36, 36, 10, 10, 64, 102, 100, 16, 12, 100, 216, 370, 256, 26, 14, 144, 390, 940, 1232, 676, 42, 16, 196, 636, 1950, 3776, 4238, 1764, 68, 18, 256, 966, 3560, 9072, 15652, 14406, 4624, 110, 20, 324, 1392, 5950, 18688, 43498, 64176, 49164
Offset: 1

Views

Author

R. H. Hardin Feb 16 2012

Keywords

Comments

Table starts
..2....4.....6......8.....10......12......14.......16.......18.......20
..4...16....36.....64....100.....144.....196......256......324......400
..6...36...102....216....390.....636.....966.....1392.....1926.....2580
.10..100...370....940...1950....3560....5950.....9320....13890....19900
.16..256..1232...3776...9072...18688...34608....59264....95568...146944
.26..676..4238..15652..43498..101036..207298...388232...677898..1119716
.42.1764.14406..64176.206514..541380.1231650..2524704..4777290..8483748
.68.4624.49164.263976.982940.2906592.7328836.16436824.33693660.64313720

Examples

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

Crossrefs

Column 1 is A006355(n+2)
Column 2 is A206981
Row 2 is A016742
Row 3 is A086113

Formula

Empirical for row n:
n=1: a(k) = 2*k
n=2: a(k) = 4*k^2
n=3: a(k) = 2*k^3 + 6*k^2 - 2*k
n=4: a(k) = (5/6)*k^4 + (35/3)*k^3 - (5/6)*k^2 - (5/3)*k
n=5: a(k) = (4/15)*k^5 + (32/3)*k^4 + (44/3)*k^3 - (32/3)*k^2 + (16/15)*k
n=6: a(k) = (13/180)*k^6 + (143/20)*k^5 + (1235/36)*k^4 - (39/4)*k^3 - (377/45)*k^2 + (13/5)*k
n=7: a(k) = (1/60)*k^7 + (77/20)*k^6 + (2527/60)*k^5 + (119/4)*k^4 - (644/15)*k^3 + (42/5)*k^2 + (4/5)*k

A207403 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 8, 12, 81, 102, 64, 10, 16, 144, 289, 216, 100, 12, 20, 256, 612, 729, 390, 144, 14, 25, 400, 1296, 1782, 1521, 636, 196, 16, 30, 625, 2340, 4356, 4212, 2809, 966, 256, 18, 36, 900, 4225, 8910, 11664, 8692, 4761, 1392, 324, 20, 42, 1296
Offset: 1

Views

Author

R. H. Hardin Feb 17 2012

Keywords

Comments

Table starts
..2...4....6....9....12.....16.....20.....25......30......36.......42.......49
..4..16...36...81...144....256....400....625.....900....1296.....1764.....2401
..6..36..102..289...612...1296...2340...4225....6890...11236....17066....25921
..8..64..216..729..1782...4356...8910..18225...33210...60516...101598...170569
.10.100..390.1521..4212..11664..26676..61009..123006..248004...456666...840889
.12.144..636.2809..8692..26896..68060.172225..380970..842724..1690038..3389281
.14.196..966.4761.16284..55696.154580.429025.1033590.2490084..5404650.11730625
.16.256.1392.7569.28362.106276.321110.970225.2529480.6594624.15405432.35988001

Examples

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

Crossrefs

Column 2 is A016742
Column 3 is A086113
Row 1 is A002620(n+2)
Row 2 is A030179(n+2)
Row 3 is A207118

Formula

Empirical for column k:
k=1: a(n) = 2*n
k=2: a(n) = 4*n^2
k=3: a(n) = 2*n^3 + 6*n^2 - 2*n
k=4: a(n) = n^4 + 6*n^3 + 7*n^2 - 6*n + 1
k=5: a(n) = (1/3)*n^5 + 3*n^4 + (28/3)*n^3 + 7*n^2 - (29/3)*n + 2
k=6: a(n) = (1/9)*n^6 + (4/3)*n^5 + (58/9)*n^4 + (40/3)*n^3 + (49/9)*n^2 - (44/3)*n + 4
k=7: a(n) = (1/36)*n^7 + (4/9)*n^6 + (53/18)*n^5 + (91/9)*n^4 + (589/36)*n^3 + (31/9)*n^2 - (58/3)*n + 6

A207703 T(n,k) = Number of n X k 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 8, 15, 81, 102, 64, 10, 25, 225, 289, 216, 100, 12, 40, 625, 1071, 729, 390, 144, 14, 64, 1600, 3969, 3321, 1521, 636, 196, 16, 104, 4096, 13230, 15129, 8151, 2809, 966, 256, 18, 169, 10816, 44100, 61254, 43681, 17225, 4761, 1392
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2012

Keywords

Comments

Table starts
..2...4....6....9....15.....25......40.......64.......104.......169........273
..4..16...36...81...225....625....1600.....4096.....10816.....28561......74529
..6..36..102..289..1071...3969...13230....44100....153090....531441....1815939
..8..64..216..729..3321..15129...61254...248004...1050282...4447881...18510693
.10.100..390.1521..8151..43681..206910...980100...4863870..24137569..117661437
.12.144..636.2809.17225.105625..571350..3090564..17518470..99301225..552967815
.14.196..966.4761.32775.225625.1369900..8317456..52895444.336392281.2102483853
.16.256.1392.7569.57681.439569.2956980.19891600.140048460.986022801.6826106385

Examples

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

Crossrefs

Column 2 is A016742.
Column 3 is A086113.
Column 4 is A207399.
Row 1 is A006498(n+2).
Row 2 is A189145(n+2).

A208287 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 10, 36, 36, 8, 16, 100, 102, 64, 10, 26, 256, 378, 216, 100, 12, 42, 676, 1260, 984, 390, 144, 14, 68, 1764, 4374, 3984, 2090, 636, 196, 16, 110, 4624, 14946, 16872, 9900, 3900, 966, 256, 18, 178, 12100, 51384, 70216, 49130, 21096, 6650, 1392
Offset: 1

Views

Author

R. H. Hardin Feb 25 2012

Keywords

Comments

Table starts
..2...4....6....10....16.....26......42.......68.......110........178
..4..16...36...100...256....676....1764.....4624.....12100......31684
..6..36..102...378..1260...4374...14946....51384....176238.....605022
..8..64..216...984..3984..16872...70216...294192...1229400....5142728
.10.100..390..2090..9900..49130..239490..1175440...5754050...28195750
.12.144..636..3900.21096.119580..665892..3733080..20874900..116842500
.14.196..966..6650.40376.256774.1604862.10095932..63357434..397965218
.16.256.1392.10608.71360.502416.3478160.24229696.168399632.1171405168

Examples

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

Crossrefs

Column 2 is A016742
Column 3 is A086113
Row 1 is A006355(n+2)
Row 2 is A206981
Row 3 is A060521

Formula

Empirical for column k:
k=1: a(n) = 2*n
k=2: a(n) = 4*n^2
k=3: a(n) = 2*n^3 + 6*n^2 - 2*n
k=4: a(n) = (4/3)*n^4 + 10*n^3 + (2/3)*n^2 - 2*n
k=5: a(n) = (5/6)*n^5 + 9*n^4 + (91/6)*n^3 - 9*n^2
k=6: a(n) = (8/15)*n^6 + (23/3)*n^5 + (82/3)*n^4 + (1/3)*n^3 - (178/15)*n^2 + 2*n
k=7: a(n) = (61/180)*n^7 + (121/20)*n^6 + (1157/36)*n^5 + (425/12)*n^4 - (2923/90)*n^3 - (22/15)*n^2 + 2*n

A209650 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 0 1 vertically.

Original entry on oeis.org

2, 4, 4, 6, 16, 6, 9, 36, 36, 8, 14, 81, 102, 64, 10, 22, 196, 270, 216, 100, 12, 35, 484, 798, 630, 390, 144, 14, 56, 1225, 2354, 2156, 1215, 636, 196, 16, 90, 3136, 7210, 7128, 4690, 2079, 966, 256, 18, 145, 8100, 22232, 24990, 16830, 8904, 3276, 1392, 324, 20, 234
Offset: 1

Views

Author

R. H. Hardin Mar 11 2012

Keywords

Comments

Table starts
..2...4....6....9....14.....22.....35......56.......90......145.......234
..4..16...36...81...196....484...1225....3136.....8100....21025.....54756
..6..36..102..270...798...2354...7210...22232....69570...218950....693810
..8..64..216..630..2156...7128..24990...87136...311040..1112150...4018716
.10.100..390.1215..4690..16830..65765..251160...994050..3911375..15639390
.12.144..636.2079..8904..34012.145775..597856..2579940.10954895..47622744
.14.196..966.3276.15386..61754.287140.1247736..5805450.26247900.122620446
.16.256.1392.4860.24808.103664.518700.2364992.11769120.56106300.279344520

Examples

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

Crossrefs

Column 2 is A016742
Column 3 is A086113
Row 1 is A001611(n+2)
Row 2 is A207436
Row 3 is A207747

Formula

Empirical for column k:
k=1: a(n) = 2*n
k=2: a(n) = 4*n^2
k=3: a(n) = 2*n^3 + 6*n^2 - 2*n
k=4: a(n) = 9*n^3 + (9/2)*n^2 - (9/2)*n
k=5: a(n) = (7/2)*n^4 + 21*n^3 - (7/2)*n^2 - 7*n
k=6: a(n) = 22*n^4 + (88/3)*n^3 - 22*n^2 - (22/3)*n
k=7: a(n) = 7*n^5 + 70*n^4 + (35/3)*n^3 - (105/2)*n^2 - (7/6)*n

A032260 Number of n X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing.

Original entry on oeis.org

2, 16, 102, 528, 2470, 11016, 47950, 205792, 874998, 3694920, 15519262, 64899456, 270415262, 1123264408, 4653525150, 19234571968, 79342610902, 326704870152, 1343120023678, 5513861152000, 22606830725598, 92580354402712, 378737813468542, 1547884976787648
Offset: 1

Views

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Jun 25 2003

Keywords

Crossrefs

The number of n X n 0, 1 matrices such that each row and each column is increasing is in sequence A000984.

Formula

a(n) = 2*n*(binomial(2*n, n)-n). G.f.: 4*x/(1-4*x)^(3/2)-2*x*(1+x)/(1-x)^3. - Vladimir Baltic and Vladeta Jovovic, Jul 10 2003

Extensions

Extended by Vladimir Baltic and Vladeta Jovovic, Jul 10 2003
More terms from Eric M. Schmidt, May 01 2013

A202052 T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 110 in rows and columns.

Original entry on oeis.org

102, 216, 216, 390, 528, 390, 636, 1080, 1080, 636, 966, 1968, 2470, 1968, 966, 1392, 3304, 4980, 4980, 3304, 1392, 1926, 5216, 9170, 11016, 9170, 5216, 1926, 2580, 7848, 15760, 22092, 22092, 15760, 7848, 2580, 3366, 11360, 25650, 41088, 47950, 41088
Offset: 1

Views

Author

R. H. Hardin Dec 10 2011

Keywords

Comments

Table starts
..102...216...390....636....966....1392....1926.....2580.....3366.....4296
..216...528..1080...1968...3304....5216....7848....11360....15928....21744
..390..1080..2470...4980...9170...15760...25650....39940....59950....87240
..636..1968..4980..11016..22092...41088...71964...120000...192060...296880
..966..3304..9170..22092..47950...95984..180054...320180...544390...890904
.1392..5216.15760..41088..95984..205792..411696...777760..1400080..2418432
.1926..7848.25650..71964.180054..411696..874998..1750140..3325410..6046344
.2580.11360.39940.120000.320180..777760.1750140..3694920..7390020.14108400
.3366.15928.59950.192060.544390.1400080.3325410..7390020.15519262.31038744
.4296.21744.87240.296880.890904.2418432.6046344.14108400.31038744.64899456

Examples

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

Crossrefs

Column 1 is A086113(n+2)
Column 2 is A086114(n+2)
Column 3 is A086115(n+2)
Diagonal is A032260(n+2)

Formula

Empirical (via A086113): T(n,k)=2*(n+2)*(2*binomial(n+k+3,n+2)-k-2)
Empirical for columns:
T(n,1) = 2*n^3 + 18*n^2 + 46*n + 36
T(n,2) = (2/3)*n^4 + (28/3)*n^3 + (142/3)*n^2 + (284/3)*n + 64
T(n,3) = (1/6)*n^5 + (10/3)*n^4 + (155/6)*n^3 + (290/3)*n^2 + 164*n + 100
T(n,4) = (1/30)*n^6 + (9/10)*n^5 + (59/6)*n^4 + (111/2)*n^3 + (2552/15)*n^2 + (1278/5)*n + 144
T(n,5) = (1/180)*n^7 + (7/36)*n^6 + (511/180)*n^5 + (805/36)*n^4 + (4606/45)*n^3 + (2443/9)*n^2 + (1854/5)*n + 196
T(n,6) = (1/1260)*n^8 + (11/315)*n^7 + (59/90)*n^6 + (308/45)*n^5 + (7807/180)*n^4 + (7667/45)*n^3 + (14139/35)*n^2 + (17876/35)*n + 256
T(n,7) = (1/10080)*n^9 + (3/560)*n^8 + (211/1680)*n^7 + (67/40)*n^6 + (6709/480)*n^5 + (6041/80)*n^4 + (663941/2520)*n^3 + (79913/140)*n^2 + (4735/7)*n + 324

A086115 Number of 5 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing.

Original entry on oeis.org

10, 100, 390, 1080, 2470, 4980, 9170, 15760, 25650, 39940, 59950, 87240, 123630, 171220, 232410, 309920, 406810, 526500, 672790, 849880, 1062390, 1315380, 1614370, 1965360, 2374850, 2849860, 3397950, 4027240, 4746430, 5564820
Offset: 1

Views

Author

Keywords

Crossrefs

Formula

a(n) = (1/6)*n*(n^4+10*n^3+35*n^2+50*n-36). More generally, number of m X n (0, 1) matrices such that each row and each column is increasing or decreasing is 2*n*(2*binomial(n+m-1, n)-m) = 4/Beta(m, n)-2*m*n.
G.f.: -10*x*(x^4-4*x^3+6*x^2-4*x-1) / (x-1)^6. [Colin Barker, Feb 22 2013]

A086114 Number of 4 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing.

Original entry on oeis.org

8, 64, 216, 528, 1080, 1968, 3304, 5216, 7848, 11360, 15928, 21744, 29016, 37968, 48840, 61888, 77384, 95616, 116888, 141520, 169848, 202224, 239016, 280608, 327400, 379808, 438264, 503216, 575128, 654480, 741768, 837504, 942216, 1056448
Offset: 1

Views

Author

Keywords

Crossrefs

Formula

a(n) = (2/3)*n*(n^3+6*n^2+11*n-6). More generally, number of m X n (0, 1) matrices such that each row and each column is increasing or decreasing is 2*n*(2*binomial(n+m-1, n)-m) = 4/Beta(m, n)-2*m*n.
G.f.: -8*x*(x^3-3*x^2+3*x+1) / (x-1)^5. [Colin Barker, Feb 22 2013]
Showing 1-10 of 10 results.