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 12 results. Next

A268880 Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 5, 84, 4133, 317966, 55491832, 19876401224, 15564645769042, 26617222097087230, 99905925686618815012, 832547140418699137884096, 15355865014207234684746438192, 632296902429868672596327438625296
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Diagonal of A268886.

Examples

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

Crossrefs

Cf. A268886.

A268881 Number of n X 3 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

2, 14, 84, 462, 2418, 12252, 60666, 295230, 1417452, 6732102, 31690914, 148080468, 687592338, 3175567374, 14597507076, 66827528094, 304831251762, 1386004252620, 6283722000714, 28414577975934, 128187044049948, 577056144993366
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Examples

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

Crossrefs

Column 3 of A268886.

Formula

Empirical: a(n) = 10*a(n-1) - 31*a(n-2) + 30*a(n-3) - 9*a(n-4).
Empirical g.f.: 2*x*(1 - 2*x)*(1 - x + x^2) / (1 - 5*x + 3*x^2)^2. - Colin Barker, Jan 15 2019

A268882 Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

5, 54, 501, 4133, 31956, 236960, 1706732, 12034000, 83485488, 571836176, 3876692480, 26059576704, 173934499008, 1153927868416, 7615733792000, 50035609197824, 327432063642624, 2135189929320448, 13880060602788864
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Examples

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

Crossrefs

Column 4 of A268886.

Formula

Empirical: a(n) = 16*a(n-1) - 88*a(n-2) + 200*a(n-3) - 208*a(n-4) + 96*a(n-5) - 16*a(n-6) for n>7.
Empirical g.f.: x*(5 - 26*x + 77*x^2 - 131*x^3 + 156*x^4 - 80*x^5 + 4*x^6) / (1 - 8*x + 12*x^2 - 4*x^3)^2. - Colin Barker, Jan 15 2019

A268883 Number of nX5 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

10, 158, 2190, 27130, 317966, 3596174, 39670270, 429588382, 4585939726, 48401059362, 506108414670, 5251396681678, 54134020936742, 554930619106590, 5661171443312270, 57509255942550986, 582036972222995470
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Column 5 of A268886.

Examples

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

Crossrefs

Cf. A268886.

Formula

Empirical: a(n) = 26*a(n-1) -241*a(n-2) +994*a(n-3) -2060*a(n-4) +2218*a(n-5) -1201*a(n-6) +290*a(n-7) -25*a(n-8) for n>9

A268884 Number of nX6 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

20, 475, 9996, 186732, 3283890, 55491832, 911930096, 14681855846, 232688402028, 3642322709900, 56444213311842, 867475989937560, 13239446101273360, 200865483664370358, 3031934392327858732, 45561723449682618252
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Column 6 of A268886.

Examples

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

Crossrefs

Cf. A268886.

Formula

Empirical: a(n) = 42*a(n-1) -665*a(n-2) +5138*a(n-3) -21972*a(n-4) +55274*a(n-5) -83769*a(n-6) +76202*a(n-7) -40273*a(n-8) +11304*a(n-9) -1296*a(n-10) for n>12

A268885 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

38, 1340, 42362, 1187838, 31427480, 800733668, 19876401224, 483987898760, 11611969197776, 275345016177616, 6466964539799840, 150689548401385312, 3487912674084234304, 80273121207141357120, 1838370376874099584640
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Column 7 of A268886.

Examples

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

Crossrefs

Cf. A268886.

Formula

Empirical: a(n) = 68*a(n-1) -1804*a(n-2) +24560*a(n-3) -195400*a(n-4) +974752*a(n-5) -3171360*a(n-6) +6871936*a(n-7) -9999248*a(n-8) +9740096*a(n-9) -6250176*a(n-10) +2552576*a(n-11) -621824*a(n-12) +79872*a(n-13) -4096*a(n-14) for n>16

A268887 Number of 2 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 5, 14, 54, 158, 475, 1340, 3740, 10204, 27521, 73354, 193842, 508346, 1324791, 3433720, 8858104, 22757432, 58253885, 148634502, 378142446, 959527766, 2429034323, 6135877428, 15469187604, 38929330452, 97806402617, 245354321666
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Examples

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

Crossrefs

Row 2 of A268886.

Formula

Empirical: a(n) = 2*a(n-1) + 5*a(n-2) - 4*a(n-3) - 11*a(n-4) - 6*a(n-5) - a(n-6).
Empirical g.f.: x^2*(5 + 4*x + x^2) / ((1 + x)^2*(1 - 2*x - x^2)^2). - Colin Barker, Jan 15 2019

A268888 Number of 3 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 20, 84, 501, 2190, 9996, 42362, 178400, 732378, 2974934, 11933578, 47466417, 187325260, 734639334, 2865135348, 11121381104, 42989239524, 165564387000, 635557701344, 2432620417837, 9286486715514, 35366757558512, 134400104565934
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Examples

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

Crossrefs

Row 3 of A268886.

Formula

Empirical: a(n) = 3*a(n-1) + 12*a(n-2) - 16*a(n-3) - 62*a(n-4) - 34*a(n-5) + 16*a(n-6) + 12*a(n-7) - a(n-8) - a(n-9).
Empirical g.f.: x^2*(2 - x)*(10 + 17*x + 13*x^2 + 6*x^3 + 2*x^4) / ((1 + x)*(1 - 2*x - 6*x^2 + x^4)^2). - Colin Barker, Jan 15 2019

A268889 Number of 4Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 71, 462, 4133, 27130, 186732, 1187838, 7529253, 46440962, 283673207, 1710265892, 10226321520, 60660804228, 357586190291, 2096177689750, 12229766790505, 71054027831574, 411303965509420, 2373090804832634
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Row 4 of A268886.

Examples

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

Crossrefs

Cf. A268886.

Formula

Empirical: a(n) = 2*a(n-1) +39*a(n-2) +14*a(n-3) -482*a(n-4) -1102*a(n-5) -111*a(n-6) +1758*a(n-7) +982*a(n-8) -1114*a(n-9) -743*a(n-10) +394*a(n-11) +206*a(n-12) -90*a(n-13) -17*a(n-14) +10*a(n-15) -a(n-16)

A268890 Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 235, 2418, 31956, 317966, 3283890, 31427480, 299524050, 2777161184, 25505113994, 231143340184, 2077724593805, 18526267129268, 164165431218906, 1446558738555296, 12686251671077220, 110791183092125102
Offset: 1

Views

Author

R. H. Hardin, Feb 15 2016

Keywords

Comments

Row 5 of A268886.

Examples

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

Crossrefs

Cf. A268886.

Formula

Empirical: a(n) = 2*a(n-1) +97*a(n-2) +116*a(n-3) -2923*a(n-4) -10986*a(n-5) +4951*a(n-6) +72992*a(n-7) +36740*a(n-8) -223968*a(n-9) -159382*a(n-10) +423052*a(n-11) +256370*a(n-12) -539504*a(n-13) -176570*a(n-14) +450908*a(n-15) +6166*a(n-16) -217920*a(n-17) +57416*a(n-18) +45120*a(n-19) -25021*a(n-20) +562*a(n-21) +2089*a(n-22) -388*a(n-23) -31*a(n-24) +14*a(n-25) -a(n-26)
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