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

A281199 Number of n X 2 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 2, 10, 38, 130, 420, 1308, 3970, 11822, 34690, 100610, 289032, 823800, 2332418, 6566290, 18394910, 51310978, 142587180, 394905492, 1090444930, 3002921270, 8249479162, 22612505090, 61857842448, 168903452400, 460409998850
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1. .0..0. .0..0. .0..1. .0..1. .0..1. .0..1. .0..1. .0..0. .0..1
..0..0. .1..0. .1..1. .0..0. .1..1. .0..1. .0..1. .1..0. .0..1. .1..1
..0..1. .0..1. .0..1. .0..1. .0..0. .1..0. .1..1. .0..1. .0..0. .0..1
..1..0. .1..1. .1..1. .0..1. .1..0. .0..0. .0..0. .1..1. .1..0. .0..0
		

Crossrefs

Column 2 of A281205.

Formula

Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4).
Conjectures from Colin Barker, Feb 16 2019: (Start)
G.f.: 2*x^2*(1 - x) / (1 - 3*x + x^2)^2.
a(n) = (2^(-n)*(2*sqrt(5)*((3-sqrt(5))^n - (3+sqrt(5))^n) - 5*(3-sqrt(5))^n*(1+sqrt(5))*n + 5*(-1+sqrt(5))*(3+sqrt(5))^n*n)) / 25.
(End)

A281200 Number of n X 3 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

1, 14, 56, 168, 448, 1120, 2688, 6272, 14336, 32256, 71680, 157696, 344064, 745472, 1605632, 3440640, 7340032, 15597568, 33030144, 69730304, 146800640, 308281344, 645922816, 1350565888, 2818572288, 5872025600, 12213813248, 25367150592
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1..0. .0..1..1. .0..0..1. .0..1..0. .0..0..1. .0..0..0. .0..1..1
..1..1..0. .0..1..0. .1..0..1. .0..1..1. .1..1..0. .1..1..0. .1..0..1
..0..1..0. .0..1..0. .1..0..1. .1..0..1. .0..1..0. .0..1..0. .1..0..1
..0..1..0. .0..1..0. .1..1..0. .1..0..0. .0..1..0. .0..1..1. .0..1..0
		

Crossrefs

Column 3 of A281205.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) for n>3.
Conjectures from Colin Barker, Feb 16 2019: (Start)
G.f.: x*(1 + 10*x + 4*x^2) / (1 - 2*x)^2.
a(n) = 7*2^(n-1) * (n-1) for n>1.
(End)

A281201 Number of n X 4 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

2, 28, 98, 270, 676, 1588, 3604, 7960, 17254, 36848, 77776, 162610, 337292, 694982, 1423852, 2902806, 5892558, 11916410, 24017514, 48262212, 96719706, 193358890, 385702166, 767826768, 1525708160, 3026506470, 5994196442, 11854696726
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..0..1..0. .0..0..1..1. .0..0..1..1. .0..1..0..1. .0..1..0..1
..1..0..1..1. .1..0..0..1. .1..0..0..0. .0..1..1..0. .0..1..0..1
..1..0..0..0. .1..1..0..1. .1..0..1..0. .0..0..1..0. .1..0..1..0
..1..0..1..1. .0..1..1..1. .1..0..1..0. .1..0..1..1. .1..0..0..0
		

Crossrefs

Column 4 of A281205.

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 4*a(n-3) - 6*a(n-4) + 2*a(n-5) + 4*a(n-6) - a(n-8).
Empirical g.f.: 2*x*(1 + x)*(1 + 11*x + 7*x^2 - 8*x^3 - 9*x^4 + 2*x^6) / (1 - x - 2*x^2 + x^4)^2. - Colin Barker, Feb 16 2019

A281202 Number of n X 5 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

5, 52, 176, 470, 1141, 2602, 5712, 12208, 25577, 52784, 107636, 217370, 435473, 866550, 1714460, 3375236, 6616061, 12919308, 25142632, 48783294, 94395997, 182209890, 350933080, 674521464, 1294078657, 2478473672, 4739410828
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1..0..1..0. .0..1..1..0..1. .0..1..0..0..1. .0..1..1..0..1
..0..0..0..1..0. .0..0..1..0..1. .1..0..1..0..1. .0..1..0..1..0
..0..1..0..1..0. .1..1..1..0..1. .1..0..1..0..1. .0..1..0..1..1
..1..0..1..0..1. .1..0..1..0..0. .0..1..0..1..0. .0..1..0..0..1
		

Crossrefs

Column 5 of A281205.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-4) + 4*a(n-5) - a(n-8).
Empirical g.f.: x*(5 + 32*x - 12*x^2 - 26*x^3 - 25*x^4 + 2*x^5 + 12*x^6 + 4*x^7) / ((1 - x)^2*(1 - x - x^2 - x^3)^2). - Colin Barker, Feb 17 2019

A281203 Number of n X 6 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

10, 94, 310, 804, 1906, 4248, 9118, 19026, 38916, 78356, 155834, 306840, 599204, 1162074, 2240438, 4297644, 8207494, 15613762, 29601530, 55948952, 105457480, 198283598, 371980528, 696408816, 1301351164, 2427600480, 4521378510
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1..0..0..1..0. .0..0..1..0..1..0. .0..1..0..1..0..0. .0..0..1..0..1..0
..0..1..1..0..1..0. .1..0..1..0..1..1. .1..0..1..0..1..0. .1..0..1..0..1..0
..1..0..1..0..1..0. .0..1..0..1..0..1. .1..0..1..0..1..0. .1..0..1..0..1..0
..0..1..0..1..0..1. .0..1..0..1..0..1. .1..0..1..0..1..0. .1..0..1..0..0..0
		

Crossrefs

Column 6 of A281205.

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 4*a(n-3) - 6*a(n-4) + 4*a(n-6) + 6*a(n-7) + 3*a(n-8) - 2*a(n-9) - 3*a(n-10) - 2*a(n-11) - a(n-12).
Empirical g.f.: 2*x*(1 + x)*(5 + 32*x + 14*x^2 - 43*x^3 - 55*x^4 - 31*x^5 + x^6 + 28*x^7 + 24*x^8 + 10*x^9 + 3*x^10) / (1 - x - 2*x^2 + x^4 + x^5 + x^6)^2. - Colin Barker, Feb 17 2019

A281204 Number of n X 7 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

20, 166, 537, 1358, 3137, 6838, 14375, 29416, 58984, 116466, 227134, 438532, 839659, 1596460, 3017310, 5673426, 10619999, 19801344, 36791933, 68149580, 125882603, 231941798, 426388234, 782226746, 1432314394, 2618121324, 4778002317
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1..0..0..1..1..0. .0..1..0..0..1..0..1. .0..1..0..0..1..0..0
..0..1..1..0..1..0..1. .0..1..1..0..1..0..1. .0..1..1..0..1..1..0
..0..0..1..0..1..0..0. .0..0..1..0..1..1..0. .1..0..1..0..0..1..1
..1..0..1..0..1..1..0. .1..0..1..0..1..0..1. .1..0..1..1..0..0..1
		

Crossrefs

Column 7 of A281205.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-4) + 4*a(n-5) - 2*a(n-6) + 4*a(n-7) - a(n-8) - 2*a(n-10) - a(n-12).
Empirical g.f.: x*(20 + 86*x - 47*x^2 - 126*x^3 - 107*x^4 - 26*x^5 + 21*x^6 + 88*x^7 + 92*x^8 + 56*x^9 + 23*x^10 + 10*x^11) / ((1 - 2*x + x^2 - x^3)^2*(1 - x^2 - x^3)^2). - Colin Barker, Feb 18 2019

A281206 Number of 2 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 2, 14, 28, 52, 94, 166, 290, 502, 864, 1480, 2526, 4298, 7294, 12350, 20868, 35196, 59262, 99630, 167258, 280422, 469576, 785424, 1312318, 2190482, 3652854, 6086126, 10131820, 16853572, 28013854, 46531510, 77237906, 128126038, 212413104
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..0..1..0. .0..1..0..0. .0..0..0..1. .0..0..1..1. .0..0..1..0
..0..1..0..1. .0..1..1..1. .0..1..0..0. .1..0..1..0. .1..1..0..1
		

Crossrefs

Row 2 of A281205.

Formula

Empirical: a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5) for n>7.
Empirical g.f.: 2*x^2*(1 + 4*x - 6*x^2 - 6*x^3 + 3*x^4 + 2*x^5) / ((1 - x)*(1 - x - x^2)^2). - Colin Barker, Feb 18 2019

A281207 Number of 3 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 10, 56, 98, 176, 310, 537, 922, 1573, 2672, 4524, 7640, 12875, 21658, 36375, 61006, 102184, 170954, 285693, 476954, 795497, 1325596, 2207076, 3671788, 6103951, 10139930, 16833147, 27926522, 46302368, 76725022, 127066209, 210326170
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..0..1..0. .0..1..1..1. .0..0..1..0. .0..1..0..1. .0..1..0..1
..1..0..1..0. .0..1..0..1. .1..1..1..0. .1..0..1..0. .1..0..1..0
..1..0..0..1. .0..1..0..1. .0..0..1..0. .1..0..0..0. .1..0..0..1
		

Crossrefs

Row 3 of A281205.

Formula

Empirical: a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5) for n>8.
Empirical g.f.: x^2*(10 + 26*x - 60*x^2 - 32*x^3 + 38*x^4 + 11*x^5 - 5*x^6) / ((1 - x)*(1 - x - x^2)^2). - Colin Barker, Feb 18 2019

A281208 Number of 4 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 38, 168, 270, 470, 804, 1358, 2284, 3834, 6432, 10786, 18080, 30290, 50712, 84838, 141812, 236846, 395228, 658966, 1097796, 1827410, 3039624, 5052282, 8391768, 13929370, 23106544, 38306878, 63470044, 105104774, 173959572, 287777246
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..0..0..1. .0..0..0..1. .0..0..1..0. .0..1..1..0. .0..0..1..0
..0..1..0..0. .1..1..0..0. .1..0..1..1. .0..0..1..1. .0..1..0..1
..0..1..1..0. .0..1..1..0. .1..0..0..1. .1..0..0..1. .0..1..0..1
..0..0..1..1. .0..0..1..0. .1..0..1..0. .1..0..1..0. .0..1..0..1
		

Crossrefs

Row 4 of A281205.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>10.
Empirical g.f.: 2*x^2*(19 + 8*x - 125*x^2 + 69*x^3 + 94*x^4 - 55*x^5 - 17*x^6 + 13*x^7 + x^8) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 18 2019

A281209 Number of 5 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

Original entry on oeis.org

0, 130, 448, 676, 1141, 1906, 3137, 5160, 8510, 14084, 23379, 38894, 64795, 108022, 180126, 300318, 500525, 833770, 1388053, 2309332, 3839550, 6379528, 10592935, 17578086, 29151695, 48317346, 80038622, 132514530, 219282785, 362687074
Offset: 1

Views

Author

R. H. Hardin, Jan 17 2017

Keywords

Examples

			Some solutions for n=4:
..0..1..0..1. .0..0..0..1. .0..1..0..0. .0..0..0..1. .0..1..1..0
..0..1..0..1. .1..1..0..1. .0..1..1..0. .0..1..0..1. .0..0..1..0
..1..0..1..0. .0..1..0..1. .0..0..1..0. .1..0..1..0. .1..0..1..0
..1..0..0..1. .0..1..0..1. .1..1..1..0. .1..0..1..0. .1..1..0..1
..1..1..0..1. .0..1..0..0. .0..0..1..1. .1..0..1..0. .0..1..0..1
		

Crossrefs

Row 5 of A281205.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>11.
Empirical g.f.: x^2*(130 - 72*x - 596*x^2 + 489*x^3 + 422*x^4 - 363*x^5 - 56*x^6 + 114*x^7 + 10*x^8 - 4*x^9) / ((1 - x)^2*(1 - x - x^2)^2). - Colin Barker, Feb 18 2019
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