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.

A269082 Number of n X n binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

2, 11, 114, 2238, 80422, 5372270, 673690710, 159449028034, 71709929917104, 61507638902069052, 100988524469068110876, 318195132133780181426070, 1928131640777904103958251102, 22507425106868892327680953474828
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Diagonal of A269089.

Examples

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

Crossrefs

Cf. A269089.

A269083 Number of n X 2 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

4, 11, 30, 76, 191, 467, 1127, 2686, 6339, 14840, 34504, 79759, 183445, 420077, 958248, 2178427, 4937234, 11159252, 25160111, 56599879, 127066227, 284728994, 636922003, 1422499564, 3172350160, 7065116255, 15714769641, 34912773337
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Examples

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

Crossrefs

Column 2 of A269089.

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*(4 + 3*x - 4*x^2 - 9*x^3 - 5*x^4 - x^5) / (1 - x - 2*x^2 - x^3)^2. - Colin Barker, Jan 19 2019

A269084 Number of n X 3 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

7, 30, 114, 428, 1531, 5387, 18590, 63347, 213490, 713237, 2365217, 7794642, 25549763, 83359179, 270860625, 876943006, 2830104798, 9107202178, 29230933367, 93601324315, 299085155918, 953808773503, 3036347307176, 9649992762591
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Examples

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

Crossrefs

Column 3 of A269089.

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*(7 + 16*x - 9*x^2 - 56*x^3 - 60*x^4 - 15*x^5 + 13*x^6 + 8*x^7 - x^8 - x^9) / ((1 + x)^2*(1 - 2*x - 3*x^2 - x^3 + x^4)^2). - Colin Barker, Jan 19 2019

A269085 Number of nX4 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

13, 76, 428, 2238, 11314, 55620, 268289, 1274435, 5982734, 27813229, 128268964, 587560638, 2675945006, 12126527636, 54715085702, 245932380152, 1101667424213, 4920048498594, 21913218006880, 97358802936939, 431593734805059
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 4 of A269089.

Examples

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

Crossrefs

Cf. A269089.

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)

A269086 Number of nX5 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

23, 191, 1531, 11314, 80422, 555789, 3761534, 25063389, 164926651, 1074440360, 6941695514, 44537043804, 284052377508, 1802408061740, 11386034886784, 71645923776799, 449267054051740, 2808501899850347, 17508131088788801
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 5 of A269089.

Examples

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

Crossrefs

Cf. A269089.

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)

A269087 Number of nX6 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

41, 467, 5387, 55620, 555789, 5372270, 50865307, 473602013, 4353444165, 39602482120, 357186481377, 3198535920085, 28468239800885, 252053488597419, 2221493915335639, 19501164969933904, 170584538930223039
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 6 of A269089.

Examples

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

Crossrefs

Cf. A269089.

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)

A269088 Number of nX7 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

72, 1127, 18590, 268289, 3761534, 50865307, 673690710, 8768989835, 112658396453, 1431998499913, 18044145807959, 225714076389625, 2806025783464923, 34698719581599414, 427098528675334433, 5235801241750340793
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 7 of A269089.

Examples

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

Crossrefs

Cf. A269089.

Formula

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