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 13 results. Next

A212943 T(n,k)=Number of nXk 0..k-1 arrays with no column j greater than or equal to than column j-1 in all rows.

Original entry on oeis.org

1, 1, 1, 1, 7, 1, 1, 181, 37, 1, 1, 10311, 9019, 175, 1, 1, 1016501, 6470341, 331489, 781, 1, 1, 152747323, 10058484751, 2509306671, 10669771, 3367, 1, 1, 32383630189, 28744943858947, 52311221188001, 801439905901, 320396041, 14197, 1, 1
Offset: 1

Views

Author

R. H. Hardin May 31 2012

Keywords

Comments

Table starts
.1...1........1............1..................1........................1
.1...7......181........10311............1016501................152747323
.1..37.....9019......6470341........10058484751...........28744943858947
.1.175...331489...2509306671.....52311221188001......2438624218076957695
.1.781.10669771.801439905901.212180664326328751.153322267564381742818531

Examples

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

Crossrefs

Column 2 is A005061

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 7*a(n-1) -12*a(n-2)
k=3: a(n) = 55*a(n-1) -936*a(n-2) +4860*a(n-3)
k=4: a(n) = 631*a(n-1) -144700*a(n-2) +15035200*a(n-3) -702208000*a(n-4) +11468800000*a(n-5)
The coefficient of a(n-1) is A209668(k) (through at least k=1..7)

A212924 Number of n X n 0..n-1 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

1, 15, 18226, 4041974015, 285912852294921876, 10046278068363977051128904352, 252848108054080530934326716965286554552380, 6218295117529777826597449794390561827118547543121719263231, 195564579665280381327483744593329391511083800439826359765867240005114671403240
Offset: 1

Views

Author

R. H. Hardin, May 31 2012

Keywords

Examples

			Some solutions for n=3:
..0..0..1....2..2..0....0..1..2....1..0..1....1..1..1....2..1..2....1..2..1
..1..2..0....1..2..0....1..2..0....1..2..2....1..0..1....1..2..2....2..1..2
..1..2..1....2..1..0....0..0..0....2..1..2....2..1..2....1..2..0....1..0..2
		

Crossrefs

Diagonal of A212930.

A212925 Number of n X 3 0..2 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

10, 568, 18226, 518320, 14230810, 386357608, 10450787266, 282343443040, 7624822644010, 205884158525848, 5558997804436306, 150094070437926160, 4052550069287319610, 109418943377927449288, 2954312294768569509346
Offset: 1

Views

Author

R. H. Hardin, May 31 2012

Keywords

Comments

Column 3 of A212930.

Examples

			Some solutions for n=3:
..2..2..2....0..1..1....1..2..1....1..0..1....0..0..0....2..1..2....2..1..0
..0..0..2....0..0..2....2..1..2....1..2..2....1..2..0....1..2..2....2..1..2
..1..2..0....0..0..2....1..0..2....2..1..2....1..2..2....1..2..0....2..1..1
		

Crossrefs

Cf. A212930.

Formula

Empirical: a(n) = 37*a(n-1) -279*a(n-2) +243*a(n-3).
Explicit formula: a(n) = 27^n - 2*9^n + 1. - Vaclav Kotesovec, May 31 2012
Empirical g.f.: 2*x*(5 + 99*x) / ((1 - x)*(1 - 9*x)*(1 - 27*x)). - Colin Barker, Jul 21 2018

A212926 Number of n X 4 0..3 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

35, 39695, 14177855, 4041974015, 1075113010175, 279128913678335, 71832238695530495, 18425105216039878655, 4720288982579567394815, 1208726373482189187710975, 309465862773085401709019135
Offset: 1

Views

Author

R. H. Hardin, May 31 2012

Keywords

Examples

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

Crossrefs

Column 4 of A212930.

Formula

Empirical: a(n) = 405*a(n-1) -43860*a(n-2) +1524160*a(n-3) -15636480*a(n-4) +14155776*a(n-5).
Empirical: a(n) = -3*96^n+256^n+36^n-1+2*16^n. - R. J. Mathar, Jun 27 2012

A212927 Number of n X 5 0..4 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

126, 4431876, 23124921876, 85800824609376, 285912852294921876, 916111390974365234376, 2891333179750701904296876, 9071116924325493011474609376, 28391912978833403911590576171876
Offset: 1

Views

Author

R. H. Hardin, May 31 2012

Keywords

Examples

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

Crossrefs

Column 5 of A212930.

Formula

Empirical: a(n) = 5251*a(n-1) -7960875*a(n-2) +4411393125*a(n-3) -945536250000*a(n-4) +70667695312500*a(n-5) -1290429687500000*a(n-6) +1220703125000000*a(n-7).
Empirical: a(n) = -2*100^n-2*25^n-4*1250^n+3*500^n+3*250^n+3125^n+1. - R. J. Mathar, Jun 27 2012

A212928 Number of nX6 0..5 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

462, 724082352, 68264066143602, 4051316109991426752, 207406617181155352354002, 10046278068363977051128904352, 475997448692406224810330915906802
Offset: 1

Views

Author

R. H. Hardin May 31 2012

Keywords

Comments

Column 6 of A212930.

Examples

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

Formula

Empirical: a(n) = 84893*a(n-1) -2276359483*a(n-2) +25831810460691*a(n-3) -141600299635779300*a(n-4) +393253940006658385200*a(n-5) -543914412861962657592000*a(n-6) +355178573601133735540800000*a(n-7) -106850312683474117501440000000*a(n-8) +12875773990520518094592000000000*a(n-9) -350101309136762266214400000000000*a(n-10) +337332030823872921600000000000000*a(n-11).
Empirical: a(n) = 46656^n -5*19440^n -1 -3*540^n -6*1800^n +6*8100^n -3375^n +400^n +4*4320^n +2*225^n +2*36^n. - R. J. Mathar, Jun 27 2012

A212929 Number of n X 7 0..6 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

1716, 163050236504, 330676305397366860, 372271852759802667094256, 346763870885473008105706659876, 300496032699305814168049256913886664, 252848108054080530934326716965286554552380
Offset: 1

Views

Author

R. H. Hardin May 31 2012

Keywords

Comments

Column 7 of A212930.

Examples

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

Formula

Empirical: a(n) = 1556535*a(n-1) -792039717385*a(n-2) +178076842413452815*a(n-3) -20358575698888213461493*a(n-4) +1266623824167234235679318755*a(n-5) -44047909952609917776536882759565*a(n-6) +864953744390957718129128593210421035*a(n-7) -9623052428363321062071131847418214552931*a(n-8) +59322745910799635132647204742065665730348485*a(n-9) -190454450982198883185256207135935908957968246875*a(n-10) +287023164786865836968027438435034735344099822518125*a(n-11) -193456826915294502754189697430417253206202705301574375*a(n-12) +48193709324773967360630681370925021204404072468778790625*a(n-13) -1968890430914107376575740256318014532178839614309088359375*a(n-14) +1920889891583479054710502398832778506621251127702072265625*a(n-15)

A212931 Number of 2Xn 0..n-1 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

1, 15, 568, 39695, 4431876, 724082352, 163050236504, 48442719007503, 18368207542264060, 8659014569831436140, 4968837728849467193040, 3410836618457710864892912, 2760233360074280192888992948
Offset: 1

Views

Author

R. H. Hardin May 31 2012

Keywords

Comments

Row 2 of A212930

Examples

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

A212932 Number of 3 X n 0..n-1 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

1, 63, 18226, 14177855, 23124921876, 68264066143602, 330676305397366860, 2450628904209116751423, 26359630332235218287361280, 394964706663355785627860751188, 7977079877065700492793254299414812
Offset: 1

Views

Author

R. H. Hardin, May 31 2012

Keywords

Comments

Row 3 of A212930.

Examples

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

Crossrefs

Cf. A212930.

A212933 Number of 4Xn 0..n-1 arrays with no column j greater than column j-1 in all rows.

Original entry on oeis.org

1, 255, 518320, 4041974015, 85800824609376, 4051316109991426752, 372271852759802667094256, 60525940157456181486116315391, 16213293097463939456656505907266320
Offset: 1

Views

Author

R. H. Hardin May 31 2012

Keywords

Comments

Row 4 of A212930

Examples

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