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.

A213089 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 3, n >= 2.

Original entry on oeis.org

4, 4, 2, 4, 8, 12, 0, 8, 4, 8, 16, 18, 14, 8, 14, 4, 8, 16, 22, 42, 24, 42, 22, 18, 4, 8, 16, 22, 48, 60, 82, 90, 66, 34, 24, 2, 4, 8, 16, 22, 50, 66, 132, 160, 218, 120, 122, 56, 36, 4, 4, 8, 16, 22, 52, 68, 144, 222, 334, 406, 302, 288, 198, 88, 52, 6, 4, 8, 16, 22, 54, 70, 152, 238, 416, 574, 810, 642, 760, 456, 320, 136, 72, 8
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3...4...5...6...7...8...9..10..11..12..13..14..15..16..17..18..19..20
.n
.2....4...4...2
.3....4...8..12...0...8
.4....4...8..16..18..14...8..14
.5....4...8..16..22..42..24..42..22..18
.6....4...8..16..22..48..60..82..90..66..34..24...2
.7....4...8..16..22..50..66.132.160.218.120.122..56..36...4
.8....4...8..16..22..52..68.144.222.334.406.302.288.198..88..52...6
.9....4...8..16..22..54..70.152.238.416..74.810.642.760.456.320.136..72...8
where k is the path length in nodes. In an attempt to define the irregularity of the array, it appears that the maximum value of k is 2n+1 for 2 <= n <= 6 and 2n+2 for n >= 7. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 3 node rectangle.
		

Crossrefs

A213478 Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths starting at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 2, n >= 2.

Original entry on oeis.org

2, 3, 4, 5, 5, 8, 7, 6, 13, 10, 8, 21, 15, 11, 10, 34, 23, 16, 13, 55, 36, 24, 18, 16, 89, 57, 37, 26, 21, 144, 91, 58, 39, 29, 26, 233, 146, 92, 60, 42, 34, 377, 235, 147, 94, 63, 47, 42, 610, 379, 236, 149, 97, 68, 55, 987, 612, 380, 238, 152, 102, 76, 68, 1597, 989, 613, 382, 241, 157, 110, 89
Offset: 2

Views

Author

Keywords

Comments

The subset of nodes approximately defines the top left-hand quarter of the rectangle and has nodal dimensions floor((n+1)/2) and 1 to capture all geometrically distinct counts.
The quarter-rectangle is read by rows.
The irregular array of numbers is:
....k.....1...2...3...4...5...6...7...8
..n
..2.......2
..3.......3...4
..4.......5...5
..5.......8...7...6
..6......13..10...8
..7......21..15..11..10
..8......34..23..16..13
..9......55..36..24..18..16
.10......89..57..37..26..21
.11.....144..91..58..39..29..26
.12.....233.146..92..60..42..34
.13.....377.235.147..94..63..47..42
.14.....610.379.236.149..97..68..55
.15.....987.612.380.238.152.102..76..68
.16....1597.989.613.382.241.157.110..89
where k indicates the position of the start node in the quarter-rectangle. For each n, the maximum value of k is floor((n+1)/2). Reading this array by rows gives the sequence.

Examples

			When n = 2, the number of times (NT) each node in the rectangle is the start node (SN) of a complete non-self-adjacent simple path is
SN 0 1
   2 3
NT 2 2
   2 2
To limit duplication, only the top left-hand corner 2 is stored in the sequence, i.e. T(2,1) = 2.
		

Crossrefs

Formula

Let T(n,k) denote an element of the irregular array then it appears that
T(n,k) = A000045(n-k+2), k = 0
T(n,k) = A000045(n-k+2) + A000045(k+1), k > 0.

Extensions

Improved Comments

A213342 Irregular array T(n,k) of numbers/2 of non-extendable non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 4, n >= 2.

Original entry on oeis.org

4, 4, 6, 6, 4, 8, 16, 18, 14, 8, 14, 4, 8, 20, 36, 44, 24, 40, 16, 84, 4, 8, 20, 40, 72, 80, 90, 66, 184, 72, 236, 26, 4, 8, 20, 40, 78, 116, 192, 180, 354, 278, 530, 268, 546, 124, 32, 4, 8, 20, 40, 80, 122, 244, 336, 628, 628, 1130, 788, 1362, 878, 1168, 354, 292, 16
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16...17...18...19...20
.n
.2....4....4....6....6
.3....4....8...16...18...14....8...14
.4....4....8...20...36...44...24...40...16...84
.5....4....8...20...40...72...80...90...66..184...72..236...26
.6....4....8...20...40...78..116..192..180..354..278..530..268..546..124...32
.7....4....8...20...40...80..122..244..336..628..628.1130..788.1362..878.1168..354..292...16
where k is the path length in nodes.
In an attempt to define the irregularity of the array, it appears that the maximum value of k is 3n for 2 <= n <= 3, 3n-1 for n = 4 and 3n - floor((n-2)/3) for n >= 5. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 4 node rectangle.
		

Crossrefs

A213375 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 5, n >= 2.

Original entry on oeis.org

4, 4, 6, 10, 10, 2, 4, 8, 16, 22, 42, 24, 42, 22, 18, 4, 8, 20, 40, 72, 80, 90, 66, 184, 72, 236, 26, 4, 8, 20, 44, 100, 136, 220, 156, 348, 244, 800, 336, 1308, 248, 56, 4, 8, 20, 44, 106, 172, 322, 410, 612, 602, 1462, 1122, 3240, 1712, 4682, 1394, 706, 218, 4
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16....17...18....19...20...21...22...23...24
.n
.2....4....4....6...10...10....2
.3....4....8...16...22...42...24...42...22...18
.4....4....8...20...40...72...80...90...66..184...72..236...26
.5....4....8...20...44..100..136..220..156..348..244..800..336.1308..248....56
.6....4....8...20...44..106..172..322..410..612..602.1462.1122.3240.1712..4682.1394...706..218...4
where k is the path length in nodes. In an attempt to define the irregularity of the array, it appears that the maximum value of k is 3n+2 for 2 <= n <= 5, 3n+3 for 6 <= n <= 9 and 3n+4 for n >= 10. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 5 node rectangle.
		

Crossrefs

A214119 Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 2, n >= 2.

Original entry on oeis.org

2, 5, 0, 10, 0, 18, 0, 0, 31, 0, 0, 52, 0, 0, 0, 86, 0, 0, 0, 141, 0, 0, 0, 0, 230, 0, 0, 0, 0, 374, 0, 0, 0, 0, 0, 607, 0, 0, 0, 0, 0, 984, 0, 0, 0, 0, 0, 0, 1594, 0, 0, 0, 0, 0, 0, 2581, 0, 0, 0, 0, 0, 0, 0, 4178, 0, 0, 0, 0, 0, 0, 0, 6762, 0, 0, 0, 0, 0, 0
Offset: 2

Views

Author

Keywords

Comments

The subset of nodes is contained in the top left-hand quarter of the rectangle and has nodal dimensions floor((n+1)/2) and 1 to capture all geometrically distinct counts. The quarter-rectangle is read by rows. The irregular array of numbers is:
....k.....1..2..3..4..5..6..7..8..9.10
..n
..2.......2
..3.......5..0
..4......10..0
..5......18..0..0
..6......31..0..0
..7......52..0..0..0
..8......86..0..0..0
..9.....141..0..0..0..0
.10.....230..0..0..0..0
.11.....374..0..0..0..0..0
.12.....607..0..0..0..0..0
.13.....984..0..0..0..0..0..0
.14....1594..0..0..0..0..0..0
.15....2581..0..0..0..0..0..0..0
.16....4178..0..0..0..0..0..0..0
.17....6762..0..0..0..0..0..0..0..0
.18...10943..0..0..0..0..0..0..0..0
.19...17708..0..0..0..0..0..0..0..0..0
.20...28654..0..0..0..0..0..0..0..0..0
where k indicates the position of the end node in the quarter-rectangle. For each n, the maximum value of k is floor((n+1)/2). Reading this array by rows gives the sequence.

Examples

			When n = 2, the number of times (NT) each node in the rectangle is the end node (EN) of a complete non-self-adjacent simple path is
EN 0 1
   2 3
NT 2 2
   2 2
To limit duplication, only the top left-hand corner 2 is stored in the sequence, i.e. T(2,1) = 2.
		

Crossrefs

Formula

Let T(n,k) denote an element of the irregular array then it appears that T(n,k) = A000045(n+3) - 3, n >= 2, k = 1 and T(n,k) = 0, n >= 2, k >= 2.

A214399 Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths incorporating each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 2, n >= 2.

Original entry on oeis.org

6, 12, 14, 23, 24, 40, 42, 40, 68, 70, 70, 113, 116, 116, 122, 186, 190, 192, 202, 304, 310, 314, 334, 334, 495, 504, 512, 546, 552, 804, 818, 832, 890, 902, 912, 1304, 1326, 1350, 1446, 1470, 1490, 2113, 2148, 2188, 2346, 2388, 2428, 2434, 3422, 3478, 3544, 3802, 3874, 3944, 3966
Offset: 2

Views

Author

Keywords

Comments

The subset of nodes is contained in the top left-hand quarter of the rectangle and has nodal dimensions floor((n+1)/2) and 1 to capture all geometrically distinct counts.
The quarter-rectangle is read by rows.
The irregular array of numbers is:
....k....1....2....3....4....5....6....7....8....9...10
..n
..2......6
..3.....12...14
..4.....23...24
..5.....40...42...40
..6.....68...70...70
..7....113..116..116..122
..8....186..190..192..202
..9....304..310..314..334..334
.10....495..504..512..546..552
.11....804..818..832..890..902..912
.12...1304.1326.1350.1446.1470.1490
.13...2113.2148.2188.2346.2388.2428.2434
.14...3422.3478.3544.3802.3874.3944.3966
.15...5540.5630.5738.6158.6278.6398.6442.6462
where k indicates the position of a node in the quarter-rectangle.
For each n, the maximum value of k is floor((n+1)/2).
Reading this array by rows gives the sequence.

Examples

			When n = 2, the number of times (NT) each node in the rectangle (N) occurs in a complete non-self-adjacent simple path is
N  0 1
   2 3
NT 6 6
   6 6
To limit duplication, only the top left-hand corner 6 is stored in the sequence, i.e. T(2,1) = 6.
		

Crossrefs

Extensions

Corrected by Christopher Hunt Gribble, Jul 19 2012

A213379 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 6, n >= 2.

Original entry on oeis.org

4, 4, 6, 10, 14, 16, 8, 4, 8, 16, 22, 48, 60, 82, 90, 66, 34, 24, 2, 4, 8, 20, 40, 78, 116, 192, 180, 354, 278, 530, 268, 546, 124, 32, 4, 8, 20, 44, 106, 172, 322, 410, 612, 602, 1462, 1122, 3240, 1712, 4682, 1394, 706, 218, 4
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16...17...18...19...20...21
.n
.2....4....4....6...10...14...16....8
.3....4....8...16...22...48...60...82...90...66...34...24....2
.4....4....8...20...40...78..116..192..180..354..278..530..268..546..124...32
.5....4....8...20...44..106..172..322..410..612..602.1462.1122.3240.1712.4682.1394..706..218....4
where k is the path length in nodes. In an attempt to define the irregularity of the array, it appears that the maximum value of k is 4n - floor((n-8)/4) for n >= 8. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 6 node rectangle.
		

Crossrefs

A213383 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 7, n >= 2.

Original entry on oeis.org

4, 4, 6, 10, 14, 20, 26, 18, 2, 4, 8, 16, 22, 50, 66, 132, 160, 218, 120, 122, 56, 36, 4, 4, 8, 20, 40, 80, 122, 244, 336, 628, 628, 1130, 788, 1362, 878, 1168, 354, 292, 16
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16...17...18...19...20
.n
.2....4....4....6...10...14...20...26...18....2
.3....4....8...16...22...50...66..132..160..218..120..122...56...36....4
.4....4....8...20...40...80..122..244..336..628..628.1130..788.1362..878.1168..354..292...16
where k is the path length in nodes. There is insufficient evidence to attempt to define the irregularity of the array. However, the maximum values of k for 2 <= n <= 11 are 11, 16, 20, 24, 29, 33, 38, 42, 46, 50. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 7 node rectangle.
		

Crossrefs

A213425 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 8, n >= 2.

Original entry on oeis.org

4, 4, 6, 10, 14, 20, 30, 40, 34, 10, 4, 8, 16, 22, 52, 68, 144, 222, 334, 406, 302, 288, 198, 88, 52, 6, 4, 8, 20, 40, 82, 124, 258, 400, 894, 1098, 1984, 1960, 2796, 2388, 3426, 2290, 2638, 1008, 1316, 152
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16...17...18...19...20...21...22
.n
.2....4....4....6...10...14...20...30...40...34...10
.3....4....8...16...22...52...68..144..222..334..406..302..288..198...88...52....6
.4....4....8...20...40...82..124..258..400..894.1098.1984.1960.2796.2388.3426.2290.2638.1008.1316..152
where k is the path length in nodes. There is insufficient evidence to attempt to define the irregularity of the array. However, the maximum values of k for 2 <= n <= 10 are 12, 18, 22, 27, 32, 38, 42, 48, 52. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 8 node rectangle.
		

Crossrefs

A213426 Irregular array T(n,k) of numbers/2 of non-extendable (complete) non-self-adjacent simple paths of each length within a square lattice bounded by rectangles with nodal dimensions n and 9, n >= 2.

Original entry on oeis.org

4, 4, 6, 10, 14, 20, 30, 44, 60, 60, 28, 2, 4, 8, 16, 22, 54, 70, 152, 238, 416, 574, 810, 642, 760, 456, 320, 136, 72, 8, 4, 8, 20, 40, 84, 126, 268, 418, 1014, 1450, 2890, 3510, 5474, 5286, 7238, 6926, 8218, 5636, 6754, 2956, 4220, 778, 48
Offset: 2

Views

Author

Keywords

Comments

The irregular array of numbers is:
...k..3....4....5....6....7....8....9...10...11...12...13...14...15...16...17...18...19...20...21...22...23...24...25
.n
.2....4....4....6...10...14...20...30...44...60...60...28....2
.3....4....8...16...22...54...70..152..238..416..574..810..642..760..456..320..136...72....8
.4....4....8...20...40...84..126..268..418.1014.1450.2890.3510.5474.5286.7238.6926.8218.5636.6754.2956.4220..778...48
where k is the path length in nodes. There is insufficient evidence to attempt to define the irregularity of the array. However, the maximum values of k for 2 <= n <= 10 are 14, 20, 25, 30, 36, 42, 48, 53. Reading this array by rows gives the sequence. One half of the numbers of paths constitute the sequence to remove the effect of the bilateral symmetry of the rectangle.

Examples

			T(2,3) = One half of the number of complete non-self-adjacent simple paths of length 3 nodes within a square lattice bounded by a 2 X 9 node rectangle.
		

Crossrefs

Showing 1-10 of 10 results.