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 1-7 of 7 results.

A268782 Number of n X n binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 5, 72, 1714, 67100, 4725018, 611932378, 148013550916, 67580406047498, 58605374440440754, 97015414668307967168, 307604236621005318739500, 1873151902121241161650454526, 21951627197224261891003815976598
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Diagonal of A268789.

Examples

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

Crossrefs

Cf. A268789.

A268783 Number of n X 2 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

1, 5, 17, 48, 131, 338, 850, 2091, 5061, 12095, 28608, 67095, 156244, 361652, 832757, 1908885, 4358285, 9915728, 22489147, 50862918, 114743814, 258261695, 580072917, 1300393467, 2910078592, 6501783407, 14504787560, 32313853992, 71896385513
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Examples

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

Crossrefs

Column 2 of A268789.

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 2*a(n-3) - 6*a(n-4) - 4*a(n-5) - a(n-6).
Empirical g.f.: x*(1 + 3*x + 4*x^2 + x^3) / (1 - x - 2*x^2 - x^3)^2. - Colin Barker, Jan 15 2019

A268784 Number of n X 3 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

2, 17, 72, 302, 1144, 4207, 14984, 52335, 179854, 610504, 2051436, 6836258, 22622554, 74418562, 243553160, 793537401, 2575357784, 8329124488, 26854438804, 86342760711, 276915214344, 886094782671, 2829527431748, 9018299661270
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Examples

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

Crossrefs

Column 3 of A268789.

Formula

Empirical: a(n) = 2*a(n-1) + 9*a(n-2) - 2*a(n-3) - 33*a(n-4) - 42*a(n-5) - 14*a(n-6) + 10*a(n-7) + 8*a(n-8) - a(n-10).
Empirical g.f.: x*(2 + 13*x + 20*x^2 + 9*x^3 - 8*x^4 - 10*x^5 - 4*x^6) / ((1 + x)^2*(1 - 2*x - 3*x^2 - x^3 + x^4)^2). - Colin Barker, Jan 15 2019

A268785 Number of nX4 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

5, 48, 302, 1714, 9085, 46195, 228384, 1105510, 5267662, 24786180, 115455033, 533317129, 2446323573, 11154503019, 50600348892, 228514035985, 1027932765869, 4607917805325, 20591918472965, 91765529043193, 407916504889146
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 4 of A268789.

Examples

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

Crossrefs

Cf. A268789.

Formula

Empirical: a(n) = 2*a(n-1) +19*a(n-2) +10*a(n-3) -122*a(n-4) -320*a(n-5) -295*a(n-6) +8*a(n-7) +176*a(n-8) +20*a(n-9) -98*a(n-10) -6*a(n-11) +43*a(n-12) -6*a(n-13) -11*a(n-14) +6*a(n-15) -a(n-16)

A268786 Number of nX5 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

10, 131, 1144, 9085, 67100, 477128, 3295246, 22302699, 148575958, 977609634, 6368239274, 41140907455, 263939673228, 1683296018391, 10680625988516, 67468330344536, 424526386272378, 2661981983940811, 16640406499054332
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 5 of A268789.

Examples

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

Crossrefs

Cf. A268789.

Formula

Empirical: a(n) = 2*a(n-1) +41*a(n-2) +54*a(n-3) -509*a(n-4) -2182*a(n-5) -2830*a(n-6) +1766*a(n-7) +7914*a(n-8) +2584*a(n-9) -10583*a(n-10) -6092*a(n-11) +11506*a(n-12) +5348*a(n-13) -11688*a(n-14) -620*a(n-15) +9251*a(n-16) -4462*a(n-17) -3137*a(n-18) +4774*a(n-19) -2365*a(n-20) +338*a(n-21) +198*a(n-22) -106*a(n-23) +12*a(n-24) +4*a(n-25) -a(n-26)

A268787 Number of nX6 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

20, 338, 4207, 46195, 477128, 4725018, 45515227, 429442918, 3988796543, 36591758790, 332327545513, 2993282062865, 26773510121640, 238060527618025, 2105957538309226, 18547209960131466, 162707970808249851
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 6 of A268789.

Examples

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

Crossrefs

Cf. A268789.

Formula

Empirical: a(n) = 2*a(n-1) +83*a(n-2) +210*a(n-3) -1918*a(n-4) -13444*a(n-5) -27431*a(n-6) +22868*a(n-7) +172414*a(n-8) +91292*a(n-9) -572846*a(n-10) -576908*a(n-11) +1569339*a(n-12) +1662464*a(n-13) -4129647*a(n-14) -2739590*a(n-15) +10005684*a(n-16) +128072*a(n-17) -18820309*a(n-18) +14239344*a(n-19) +18275195*a(n-20) -39512592*a(n-21) +16595129*a(n-22) +32600294*a(n-23) -63035320*a(n-24) +55225574*a(n-25) -27556538*a(n-26) +5959238*a(n-27) +1367780*a(n-28) -935764*a(n-29) -205936*a(n-30) +253428*a(n-31) -6946*a(n-32) -44268*a(n-33) +5192*a(n-34) +6896*a(n-35) -1085*a(n-36) -848*a(n-37) +74*a(n-38) +94*a(n-39) +3*a(n-40) -6*a(n-41) -a(n-42)

A268788 Number of nX7 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

38, 850, 14984, 228384, 3295246, 45515227, 611932378, 8057509992, 104456486696, 1337467436839, 16954554895936, 213155407369839, 2661273257222436, 33030289066656341, 407868045265169610, 5014148928763408926
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 7 of A268789.

Examples

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

Crossrefs

Cf. A268789.

Formula

Empirical recurrence of order 68 (see link above)
Showing 1-7 of 7 results.