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

A269005 Number of n X n binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 4, 46, 2136, 109058, 14382480, 3258530608, 1582785864320, 1554970236400402, 3055129067325800608, 12891237725516640144940, 106775629834644247372248448, 1932363567303596958505554161216, 68821810412730939070416537380998580
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Diagonal of A269011.

Examples

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

Crossrefs

Cf. A269011.

A269006 Number of n X 3 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

2, 8, 46, 224, 1066, 4952, 22654, 102416, 458674, 2038328, 8999374, 39512144, 172645498, 751190504, 3256354942, 14069557088, 60610482274, 260412843944, 1116181074286, 4773749750528, 20376053362762, 86813692172216
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Column 3 of A269011.

Formula

Empirical: a(n) = 10*a(n-1) - 31*a(n-2) + 24*a(n-3) + 21*a(n-4) - 18*a(n-5) - 9*a(n-6).
Empirical g.f.: 2*x*(1 - x)*(1 - 3*x)*(1 - 2*x + 3*x^2) / (1 - 5*x + 3*x^2 + 3*x^3)^2. - Colin Barker, Jan 18 2019

A269007 Number of n X 4 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

5, 36, 305, 2136, 14240, 91048, 566656, 3456320, 20760192, 123186784, 723791744, 4218132480, 24414483712, 140486492800, 804321836032, 4584741088256, 26032741150720, 147311358346752, 831044097026048, 4675403505475584
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Column 4 of A269011.

Formula

Empirical: a(n) = 12*a(n-1) - 40*a(n-2) + 8*a(n-3) + 92*a(n-4) - 32*a(n-5) - 64*a(n-6) for n>7.
Empirical g.f.: x*(5 - 24*x + 73*x^2 - 124*x^3 + 60*x^4 + 16*x^5 + 4*x^6) / (1 - 6*x + 2*x^2 + 8*x^3)^2. - Colin Barker, Jan 18 2019

A269008 Number of n X 5 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

10, 88, 1078, 10976, 109058, 1053432, 10002542, 93733440, 869397882, 7996744280, 73044076454, 663272676512, 5992284643698, 53897945082104, 482908211678430, 4311837258739840, 38381936117267690, 340717648957870424
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 5 of A269011.

Examples

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

Crossrefs

Cf. A269011.

Formula

Empirical: a(n) = 24*a(n-1) -198*a(n-2) +584*a(n-3) +137*a(n-4) -2864*a(n-5) +1132*a(n-6) +4336*a(n-7) -1391*a(n-8) -2280*a(n-9) +90*a(n-10) +200*a(n-11) -25*a(n-12).

A269009 Number of nX6 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

20, 272, 4948, 73568, 1049588, 14382480, 192100836, 2516546784, 32481770852, 414339126768, 5234937372516, 65617049910368, 816985376286500, 10114119489148976, 124593533629907540, 1528232910934667360
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 6 of A269011.

Examples

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

Crossrefs

Cf. A269011.

Formula

Empirical: a(n) = 28*a(n-1) -230*a(n-2) +192*a(n-3) +3805*a(n-4) -5776*a(n-5) -27808*a(n-6) +25744*a(n-7) +101333*a(n-8) -13916*a(n-9) -149690*a(n-10) -66848*a(n-11) +23183*a(n-12) +9888*a(n-13) -2304*a(n-14)

A269010 Number of nX7 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

38, 696, 18210, 390064, 8134304, 164351184, 3258530608, 63679868768, 1230707111424, 23573013881888, 448188039743360, 8468276406290880, 159151109503787520, 2977237536021550208, 55469798154343791232
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 7 of A269011.

Examples

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

Crossrefs

Cf. A269011.

Formula

Empirical: a(n) = 60*a(n-1) -1352*a(n-2) +13344*a(n-3) -35948*a(n-4) -311480*a(n-5) +1985472*a(n-6) +1821840*a(n-7) -31021776*a(n-8) +4125984*a(n-9) +251967152*a(n-10) -46853056*a(n-11) -1173410880*a(n-12) -138650624*a(n-13) +2912101888*a(n-14) +1295316992*a(n-15) -3360870400*a(n-16) -2339016704*a(n-17) +1368141824*a(n-18) +1168457728*a(n-19) -291553280*a(n-20) -245170176*a(n-21) +45023232*a(n-22) +19922944*a(n-23) -4194304*a(n-24) for n>25

A269012 Number of 2 X n binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 4, 8, 36, 88, 272, 696, 1900, 4856, 12588, 31792, 80288, 200304, 498004, 1229672, 3024948, 7407496, 18079664, 43980072, 106688956, 258132824, 623113020, 1500935776, 3608439104, 8659683552, 20747930788, 49635222728, 118576046148
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Row 2 of A269011.

Formula

Empirical: a(n) = 2*a(n-1) + 5*a(n-2) - 6*a(n-3) - 9*a(n-4).
Conjectures from Colin Barker, Jan 18 2019: (Start)
G.f.: 4*x^2 / (1 - x - 3*x^2)^2.
a(n) = 4*(-((1/2)*(1+sqrt(13)))^n*(sqrt(13)-13*n) + ((1/2)*(1-sqrt(13)))^n*(sqrt(13)+13*n)) / 169.
(End)

A269013 Number of 3 X n binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 15, 46, 305, 1078, 4948, 18210, 73277, 270458, 1026795, 3757996, 13847240, 50155940, 181596651, 651546278, 2331910405, 8300115170, 29460799452, 104176325510, 367430075801, 1292287850546, 4534933300095, 15878737307224
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Row 3 of A269011.

Formula

Empirical: a(n) = 4*a(n-1) + 8*a(n-2) - 34*a(n-3) - 16*a(n-4) + 60*a(n-5) - 25*a(n-6).
Empirical g.f.: x^2*(15 - 14*x + x^2) / (1 - 2*x - 6*x^2 + 5*x^3)^2. - Colin Barker, Jan 18 2019

A269014 Number of 4 X n binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 48, 224, 2136, 10976, 73568, 390064, 2291728, 12190944, 67387784, 356115520, 1906181472, 9983123936, 52432319344, 272227610848, 1412208727736, 7276913394080, 37421599567712, 191604936958480, 978880041945808
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Row 4 of A269011.

Formula

Empirical: a(n) = 4*a(n-1) + 28*a(n-2) - 78*a(n-3) - 264*a(n-4) + 296*a(n-5) + 527*a(n-6) - 252*a(n-7) - 324*a(n-8).
Empirical g.f.: 8*x^2*(6 + 4*x - 13*x^2 - 12*x^3) / (1 - 2*x - 16*x^2 + 7*x^3 + 18*x^4)^2. - Colin Barker, Jan 18 2019

A269015 Number of 5Xn binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 145, 1066, 14240, 109058, 1049588, 8134304, 69184207, 534525058, 4286305792, 32838001316, 255036784680, 1935580387968, 14746081110093, 110945210978202, 834598743197152, 6232287294972630, 46465158121063708, 344786403529703264
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Row 5 of A269011.

Examples

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

Crossrefs

Cf. A269011.

Formula

Empirical: a(n) = 8*a(n-1) +52*a(n-2) -424*a(n-3) -816*a(n-4) +6756*a(n-5) +1362*a(n-6) -38476*a(n-7) +19016*a(n-8) +82920*a(n-9) -70008*a(n-10) -50556*a(n-11) +50607*a(n-12) +9180*a(n-13) -10404*a(n-14)
Showing 1-10 of 12 results. Next