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 1-6 of 6 results.

A223504 T(n,k)=Petersen graph (3,1) coloring a rectangular array: number of nXk 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal, diagonal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0.

Original entry on oeis.org

1, 3, 6, 9, 19, 36, 27, 115, 121, 216, 81, 631, 1519, 771, 1296, 243, 3539, 16323, 20115, 4913, 7776, 729, 19759, 182901, 426359, 266419, 31307, 46656, 2187, 110427, 2030665, 9685063, 11148439, 3528715, 199497, 279936, 6561, 617015, 22598167
Offset: 1

Views

Author

R. H. Hardin Mar 21 2013

Keywords

Comments

Table starts
........1........3............9..............27.................81
........6.......19..........115.............631...............3539
.......36......121.........1519...........16323.............182901
......216......771........20115..........426359............9685063
.....1296.....4913.......266419........11148439..........515473927
.....7776....31307......3528715.......291545903........27465794119
....46656...199497.....46737819......7624417031......1463848507173
...279936..1271251....619042315....199391762123.....78024299447333
..1679616..8100769...8199214219...5214442630935...4158831849750231
.10077696.51620379.108598575915.136366781617267.221674060909378867

Examples

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

Crossrefs

Column 1 is A000400(n-1)
Column 2 is A138977
Row 1 is A000244(n-1)

Formula

Empirical for column k:
k=1: a(n) = 6*a(n-1)
k=2: a(n) = 7*a(n-1) -4*a(n-2)
k=3: a(n) = 15*a(n-1) -24*a(n-2) +10*a(n-3)
k=4: a(n) = 31*a(n-1) -127*a(n-2) -20*a(n-3) +705*a(n-4) -1027*a(n-5) +499*a(n-6) -60*a(n-7)
k=5: [order 21]
k=6: [order 53]
Empirical for row n:
n=1: a(n) = 3*a(n-1)
n=2: a(n) = 5*a(n-1) +4*a(n-2) -4*a(n-3) for n>4
n=3: a(n) = 12*a(n-1) -4*a(n-2) -73*a(n-3) +103*a(n-4) -23*a(n-5) -16*a(n-6) +4*a(n-7) for n>8
n=4: [order 21] for n>22
n=5: [order 60] for n>61

A214101 T(n,k)=Number of 0..2 colorings of an nx(k+1) array circular in the k+1 direction with new values 0..2 introduced in row major order.

Original entry on oeis.org

1, 1, 3, 3, 2, 9, 5, 19, 4, 27, 11, 30, 121, 8, 81, 21, 143, 180, 771, 16, 243, 43, 322, 2041, 1080, 4913, 32, 729, 85, 1179, 5068, 29540, 6480, 31307, 64, 2187, 171, 3110, 37441, 79968, 428383, 38880, 199497, 128, 6561, 341, 10183, 121588, 1241355, 1262128
Offset: 1

Views

Author

R. H. Hardin Jul 04 2012

Keywords

Comments

Table starts
..1..1....3....5.....11......21.......43........85........171.........341
..3..2...19...30....143.....322.....1179......3110......10183.......28842
..9..4..121..180...2041....5068....37441....121588.....722009.....2720828
.27..8..771.1080..29540...79968..1241355...4807928...54733587...263068168
.81.16.4913.6480.428383.1262128.41634729.190532944.4254090231.25595530224

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..0....2..0....1..0....1..2....1..2....1..2....1..2....2..0....1..0....1..2
..0..1....1..2....0..1....0..1....2..0....2..0....2..0....0..2....2..1....0..1
..1..2....2..0....2..0....2..0....0..2....1..2....0..1....1..0....1..2....1..0
		

Crossrefs

Column 3 is A138977
Column 4 is A052934
Row 1 is A001045
Row 2 is A094554(n+1)

Formula

Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 2*a(n-1)
k=3: a(n) = 7*a(n-1) -4*a(n-2)
k=4: a(n) = 6*a(n-1)
k=5: a(n) = 19*a(n-1) -71*a(n-2) +86*a(n-3) -24*a(n-4)
k=6: a(n) = 18*a(n-1) -36*a(n-2) +16*a(n-3)
k=7: a(n) = 54*a(n-1) -820*a(n-2) +4906*a(n-3) -11803*a(n-4) +11888*a(n-5) -4672*a(n-6) +576*a(n-7)
Empirical for row n:
n=1: a(k)=a(k-1)+2*a(k-2)
n=2: a(k)=2*a(k-1)+5*a(k-2)-6*a(k-3)
n=3: a(k)=3*a(k-1)+15*a(k-2)-33*a(k-3)-22*a(k-4)+38*a(k-5)+8*a(k-6)-8*a(k-7)
n=4: (order 11)
n=5: (order 29)
n=6: (order 40)

A209517 T(n,k) = Number of (n+1) X (k+1) 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to the number of counterclockwise edge increases.

Original entry on oeis.org

57, 363, 363, 2313, 4995, 2313, 14739, 68937, 68937, 14739, 93921, 951777, 2071311, 951777, 93921, 598491, 13141335, 62340543, 62340543, 13141335, 598491, 3813753, 181445643, 1876947141, 4099186545, 1876947141, 181445643, 3813753, 24302307
Offset: 1

Views

Author

R. H. Hardin, Mar 09 2012

Keywords

Comments

Table starts
.......57.........363...........2313.............14739.................93921
......363........4995..........68937............951777..............13141335
.....2313.......68937........2071311..........62340543............1876947141
....14739......951777.......62340543........4099186545..........269845393359
....93921....13141335.....1876947141......269845393359........38883961392081
...598491...181445643....56515446141....17769569448759......5607670578249789
..3813753..2505266673..1701725703867..1170258116647953....808953988260058047
.24302307.34590865185.51240520677831.77072446894479573.116711118063701004591

Examples

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

Crossrefs

Column 1 is 3*A138977(n+1).
Column 2 is 3*A138978(n+1).
Column 3 is 3*A138979(n+1).

A138978 Number of 3 X n matrices containing a 1 in the top left entry, all entries are integer values and adjacent entries differ by at most 1.

Original entry on oeis.org

9, 121, 1665, 22979, 317259, 4380445, 60481881, 835088891, 11530288395, 159201677509, 2198138788809, 30350271502115, 419054058355851, 5785987905016141, 79888633386248025, 1103043049708026539, 15230001039404897259, 210284568423392013685, 2903453493049800669321
Offset: 1

Views

Author

Wayne VanWeerthuizen, Apr 05 2008

Keywords

Comments

Horizontally or vertically adjacent entries can differ by at most 1. Diagonally adjacent entries thus differ by at most 2.

Crossrefs

Programs

  • Maple
    a:= n-> (Matrix([1,6,2]). Matrix([[3,12,2], [2,10,2], [1,6,3]])^(n-1) .Matrix([[1],[1],[1]]))[1,1]: seq(a(n), n=1..20); # Alois P. Heinz, Aug 28 2008
  • Mathematica
    LinearRecurrence[{16, -31, 10}, {9, 121, 1665}, 25] (* Paolo Xausa, Mar 17 2024 *)

Formula

a(n) = b(n)+c(n)+d(n), where b(1)=1, c(1)=6, d(1)=2, with b(n+1)=3*b(n)+2*c(n)+1*d(n), c(n+1)=12*b(n)+10*c(n)+6*d(n), d(n+1)=2*b(n)+2*c(n)+3*d(n).
G.f.: -x*(8*x^2-23*x+9) / (10*x^3-31*x^2+16*x-1). - Colin Barker, Dec 03 2012

Extensions

More terms from Alois P. Heinz, Aug 28 2008

A138979 Number of 4 X n matrices containing a 1 in the top left entry, all entries are integer values and adjacent entries differ by at most 1.

Original entry on oeis.org

27, 771, 22979, 690437, 20780181, 625649047, 18838482047, 567241901289, 17080173559277, 514300085627023, 15486061794514775, 466299978310573033, 14040733816061115637, 422779788989982722559, 12730299739840800975879, 383321378409770250813777
Offset: 1

Views

Author

Wayne VanWeerthuizen, Apr 05 2008

Keywords

Comments

Horizontally or vertically adjacent entries can differ by at most 1. Diagonally adjacent entries thus differ by at most 2.

Crossrefs

Programs

  • Maple
    a:= n-> (Matrix([2,4,4,2,4,2,2,4,2,1]). Matrix([[3,4,2,2,2,0,1,0,1,0], [2,5,3,2,3,1,1,3,2,1], [1,3,5,1,4,2,2,4,2,1], [2,4,2,3,4,2,2,4,2,1], [1,3,4,2,7,3,3,6,3,2], [0,2,4,2,6,4,2,6,2,2], [1,2,4,2,6,2,4,6,2,2], [0,3,4,2,6,3,3,7,3,2], [1,4,4,2,6,2,2,6,4,2], [0,4,4,2,8,4,4,8,4,3]])^(n-1) .Matrix([[1],[1],[1],[1],[1],[1],[1],[1],[1],[1]]))[1,1]: seq(a(n), n=1..20); # Alois P. Heinz, Aug 28 2008
  • Mathematica
    LinearRecurrence[{45, -528, 2592, -5997, 5689, 812, -4760, 1942, 278, -112}, {27, 771, 22979, 690437, 20780181, 625649047, 18838482047, 567241901289, 17080173559277, 514300085627023}, 20] (* Paolo Xausa, Mar 17 2024 *)

Formula

a(n)=b(n)+c(n)+d(n)+e(n)+f(n)+g(n)+h(n)+j(n)+k(n)+l(n), where
b(1)=2,c(1)=4,d(1)=4,e(1)=2,f(1)=4,g(1)=2,h(1)=2,j(1)=4,k(1)=2,l(1)=1
b(n+1)=3*b(n)+2*c(n)+1*d(n)+2*e(n)+1*f(n)+0*g(n)+1*h(n)+0*j(n)+1*k(n)+0*l(n)
c(n+1)=4*b(n)+5*c(n)+3*d(n)+4*e(n)+3*f(n)+2*g(n)+2*h(n)+3*j(n)+4*k(n)+4*l(n)
d(n+1)=2*b(n)+3*c(n)+5*d(n)+2*e(n)+4*f(n)+4*g(n)+4*h(n)+4*j(n)+4*k(n)+4*l(n)
e(n+1)=2*b(n)+2*c(n)+1*d(n)+3*e(n)+2*f(n)+2*g(n)+2*h(n)+2*j(n)+2*k(n)+2*l(n)
f(n+1)=2*b(n)+3*c(n)+4*d(n)+4*e(n)+7*f(n)+6*g(n)+6*h(n)+6*j(n)+6*k(n)+8*l(n)
g(n+1)=0*b(n)+1*c(n)+2*d(n)+2*e(n)+3*f(n)+4*g(n)+2*h(n)+3*j(n)+2*k(n)+4*l(n)
h(n+1)=1*b(n)+1*c(n)+2*d(n)+2*e(n)+3*f(n)+2*g(n)+4*h(n)+3*j(n)+2*k(n)+4*l(n)
j(n+1)=0*b(n)+3*c(n)+4*d(n)+4*e(n)+6*f(n)+6*g(n)+6*h(n)+7*j(n)+6*k(n)+8*l(n)
k(n+1)=1*b(n)+2*c(n)+2*d(n)+2*e(n)+3*f(n)+2*g(n)+2*h(n)+3*j(n)+4*k(n)+4*l(n)
l(n+1)=0*b(n)+1*c(n)+1*d(n)+1*e(n)+2*f(n)+2*g(n)+2*h(n)+2*j(n)+2*k(n)+3*l(n).
G.f.: -x*(-27 +116*x^9 -206*x^8 +5284*x^6 -2464*x^7 -154*x^5 +6514*x^3 -6915*x^4 -2540*x^2 +444*x) / (1 -45*x -1942*x^8 +528*x^2 -278*x^9 -2592*x^3 +112*x^10 +5997*x^4 -5689*x^5 -812*x^6 +4760*x^7). - Alois P. Heinz, Sep 02 2014

Extensions

More terms from Alois P. Heinz, Aug 28 2008

A222169 T(n,k)=Number of nXk 0..4 arrays with entries increasing mod 5 by 0, 1 or 2 rightwards and downwards, starting with upper left zero.

Original entry on oeis.org

1, 3, 3, 9, 19, 9, 27, 121, 121, 27, 81, 771, 1665, 771, 81, 243, 4913, 22979, 22979, 4913, 243, 729, 31307, 317259, 690437, 317259, 31307, 729, 2187, 199497, 4380445, 20780181, 20780181, 4380445, 199497, 2187, 6561, 1271251, 60481881, 625649047
Offset: 1

Views

Author

R. H. Hardin Feb 10 2013

Keywords

Comments

Table starts
......1..........3..............9.................27.....................81
......3.........19............121................771...................4913
......9........121...........1665..............22979.................317259
.....27........771..........22979.............690437...............20780181
.....81.......4913.........317259...........20780181.............1366395515
....243......31307........4380445..........625649047............89948464453
....729.....199497.......60481881........18838482047..........5923189816253
...2187....1271251......835088891.......567241901289........390086038882651
...6561....8100769....11530288395.....17080173559277......25690815631493191
..19683...51620379...159201677509....514300085627023....1691995329032459285
..59049..328939577..2198138788809..15486061794514775..111434983000652039093
.177147.2096095523.30350271502115.466299978310573033.7339124863989795685471

Examples

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

Crossrefs

Diagonal is A068748
Column 1 is A000244(n-1)
Column 2 is A138977
Column 3 is A138978
Column 4 is A138979

Formula

Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 7*a(n-1) -4*a(n-2)
k=3: a(n) = 16*a(n-1) -31*a(n-2) +10*a(n-3)
k=4: [order 10]
k=5: [order 25]
k=6: [order 70]
Showing 1-6 of 6 results.