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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A268026 T(n,k)=Number of nXk 0..2 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value.

Original entry on oeis.org

3, 9, 9, 27, 81, 24, 78, 729, 576, 63, 222, 6084, 13824, 3969, 159, 622, 49284, 295962, 250047, 25281, 394, 1722, 386884, 6042732, 13530274, 4019679, 155236, 957, 4719, 2965284, 117582228, 687233742, 528293442, 61162984, 915849, 2292, 12821
Offset: 1

Views

Author

R. H. Hardin, Jan 24 2016

Keywords

Comments

Table starts
.....3.........9............27..............78...............222
.....9........81...........729............6084.............49284
....24.......576.........13824..........295962...........6042732
....63......3969........250047........13530274.........687233742
...159.....25281.......4019679.......528293442.......64075543999
...394....155236......61162984.....19177213020.....5458407864352
...957....915849.....876467493....642612340592...420621575011611
..2292...5253264...12040481088..20358126145678.30224756956473940
..5419..29365561..159131975059.612589053437088
.12678.160731684.2037756289752

Examples

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

Crossrefs

Column 1 is A267960.
Column 2 is A267961.
Row 1 is A268013.
Row 2 is A268014.

Formula

Empirical for column k:
k=1: a(n) = 6*a(n-1) -9*a(n-2) -8*a(n-3) +24*a(n-4) -16*a(n-6)
k=2: [order 15]
k=3: [order 28]
Empirical for row n:
n=1: a(n) = 6*a(n-1) -9*a(n-2) -4*a(n-3) +9*a(n-4) +6*a(n-5) +a(n-6)
n=2: [order 15]
n=3: [order 86] for n>87

A269409 T(n,k)=Number of length-n 0..k arrays with no repeated value greater than or equal to the previous repeated value.

Original entry on oeis.org

2, 3, 4, 4, 9, 6, 5, 16, 24, 9, 6, 25, 60, 63, 12, 7, 36, 120, 222, 159, 16, 8, 49, 210, 570, 804, 394, 20, 9, 64, 336, 1215, 2670, 2872, 957, 25, 10, 81, 504, 2289, 6960, 12380, 10132, 2292, 30, 11, 100, 720, 3948, 15477, 39560, 56890, 35383, 5419, 36, 12, 121
Offset: 1

Views

Author

R. H. Hardin, Feb 25 2016

Keywords

Comments

Table starts
..2.....3......4.......5........6.........7.........8..........9.........10
..4.....9.....16......25.......36........49........64.........81........100
..6....24.....60.....120......210.......336.......504........720........990
..9....63....222.....570.....1215......2289......3948.......6372.......9765
.12...159....804....2670.....6960.....15477.....30744......56124......95940
.16...394...2872...12380....39560....104006....238224.....492312.....939360
.20...957..10132...56890...223320....695135...1837752....4302612....9168780
.25..2292..35383..259445..1253190...4623815..14121282...37478718...89241015
.30..5419.122480.1175355..6995660..30625210.108123624..325487010..866361210
.36.12678.420752.5293671.38870136.202067047.825227424.2819002698.8390905692

Examples

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

Crossrefs

Column 1 is A002620(n+2).
Column 2 is A267960.
Column 3 is A267928.
Diagonal is A268205.
Row 1 is A000027(n+1).
Row 2 is A000290(n+1).
Row 3 is A007531(n+2).

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4)
k=2: a(n) = 6*a(n-1) -9*a(n-2) -8*a(n-3) +24*a(n-4) -16*a(n-6)
k=3: [order 8]
k=4: [order 10]
k=5: [order 12]
k=6: [order 14]
k=7: [order 16]
Empirical for row n:
n=1: a(n) = n + 1
n=2: a(n) = n^2 + 2*n + 1
n=3: a(n) = n^3 + 3*n^2 + 2*n
n=4: a(n) = n^4 + 4*n^3 + (7/2)*n^2 + (1/2)*n
n=5: a(n) = n^5 + 5*n^4 + (11/2)*n^3 + n^2 - (1/2)*n
n=6: a(n) = n^6 + 6*n^5 + 8*n^4 + (5/3)*n^3 - n^2 + (1/3)*n
n=7: a(n) = n^7 + 7*n^6 + 11*n^5 + (8/3)*n^4 - (11/6)*n^3 + (1/3)*n^2 - (1/6)*n
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