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.

A268744 Number of n X 2 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

4, 11, 32, 89, 244, 659, 1760, 4657, 12228, 31899, 82752, 213641, 549236, 1406755, 3591232, 9140833, 23204612, 58765099, 148496608, 374496953, 942729588, 2369172915, 5944748064, 14895231121, 37272007108, 93149401019, 232527917312
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Column 2 of A268750.

Examples

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

Crossrefs

Cf. A268750.

Formula

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 4*a(n-3) - a(n-4).
Empirical g.f.: x*(4 - 5*x - 4*x^2 - x^3) / (1 - 2*x - x^2)^2. - Colin Barker, Mar 21 2018

A268743 Number of n X n binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

2, 11, 143, 4110, 255651, 34732937, 10319681062, 6744840113811, 9736268648482947, 31152408949342676906, 221573405414594347811555, 3511390061199964238627005057, 124222798189336185449669887550302
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Diagonal of A268750.

Examples

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

Crossrefs

Cf. A268750.

A268745 Number of n X 3 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

7, 32, 143, 623, 2615, 10830, 44067, 177429, 707163, 2796840, 10986379, 42911627, 166777091, 645395334, 2488065863, 9559464281, 36618142447, 139888931680, 533099140807, 2027067051095, 7692165427919, 29135580083054, 110168752548843
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Examples

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

Crossrefs

Column 3 of A268750.

Formula

Empirical: a(n) = 4*a(n-1) + 8*a(n-2) - 24*a(n-3) - 38*a(n-4) + 4*a(n-5) + 12*a(n-6) - a(n-8).
Empirical g.f.: x*(7 + 4*x - 41*x^2 - 37*x^3 + 13*x^4 + 6*x^5 + x^6 - x^7) / (1 - 2*x - 6*x^2 + x^4)^2. - Colin Barker, Jan 14 2019

A268746 Number of nX4 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

13, 89, 623, 4110, 26334, 165019, 1016807, 6183665, 37209717, 221970102, 1314544140, 7737069617, 45297553803, 263980824665, 1532201345489, 8861529601362, 51088246525260, 293694819166095, 1684057081243885
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Column 4 of A268750.

Examples

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

Crossrefs

Cf. A268750.

Formula

Empirical: a(n) = 8*a(n-1) +2*a(n-2) -82*a(n-3) -49*a(n-4) +124*a(n-5) +39*a(n-6) -58*a(n-7) -6*a(n-8) +8*a(n-9) -a(n-10)

A268747 Number of nX5 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

23, 244, 2615, 26334, 255651, 2425799, 22577073, 207252725, 1880654551, 16909709308, 150867667407, 1337324783132, 11788337576943, 103412756868981, 903363696442081, 7862056896605875, 68198486775427551, 589834799847933624
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Column 5 of A268750.

Examples

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

Crossrefs

Cf. A268750.

Formula

Empirical: a(n) = 8*a(n-1) +56*a(n-2) -288*a(n-3) -1506*a(n-4) +870*a(n-5) +7568*a(n-6) -1632*a(n-7) -15481*a(n-8) +4624*a(n-9) +13495*a(n-10) -6192*a(n-11) -4336*a(n-12) +2890*a(n-13) +82*a(n-14) -288*a(n-15) +24*a(n-16) +8*a(n-17) -a(n-18)

A268748 Number of nX6 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

41, 659, 10830, 165019, 2425799, 34732937, 487682438, 6746117783, 92215499119, 1248437108837, 16766958502992, 223674635599161, 2966748789292217, 39154974765661223, 514529476985579624, 6735601878829825279
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Column 6 of A268750.

Examples

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

Crossrefs

Cf. A268750.

Formula

Empirical: a(n) = 16*a(n-1) +60*a(n-2) -1148*a(n-3) -3346*a(n-4) +16272*a(n-5) +36588*a(n-6) -104246*a(n-7) -147989*a(n-8) +349140*a(n-9) +217324*a(n-10) -591448*a(n-11) -19320*a(n-12) +431032*a(n-13) -151921*a(n-14) -73194*a(n-15) +41684*a(n-16) +2552*a(n-17) -3594*a(n-18) +148*a(n-19) +100*a(n-20) -4*a(n-21) -a(n-22)

A268749 Number of nX7 binary arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

Original entry on oeis.org

72, 1760, 44067, 1016807, 22577073, 487682438, 10319681062, 215027310572, 4425392044505, 90177748184504, 1822495416470859, 36579128848735042, 729860195814419706, 14489046573912834959, 286363070886993749567
Offset: 1

Views

Author

R. H. Hardin, Feb 12 2016

Keywords

Comments

Column 7 of A268750.

Examples

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

Crossrefs

Cf. A268750.

Formula

Empirical: a(n) = 18*a(n-1) +325*a(n-2) -4074*a(n-3) -48747*a(n-4) +201072*a(n-5) +2225020*a(n-6) -6248320*a(n-7) -47573325*a(n-8) +135873052*a(n-9) +512366407*a(n-10) -1794441336*a(n-11) -2517416282*a(n-12) +13453431136*a(n-13) +1270823811*a(n-14) -55187301646*a(n-15) +38695555999*a(n-16) +115237077158*a(n-17) -158181613013*a(n-18) -96178246900*a(n-19) +263575852534*a(n-20) -18739881048*a(n-21) -224653932202*a(n-22) +90835575680*a(n-23) +105290165907*a(n-24) -69076575582*a(n-25) -27720217521*a(n-26) +26811874806*a(n-27) +3877126783*a(n-28) -6197138172*a(n-29) -207452034*a(n-30) +895782500*a(n-31) -10034133*a(n-32) -81777708*a(n-33) +1520627*a(n-34) +4630616*a(n-35) -28132*a(n-36) -153828*a(n-37) -2195*a(n-38) +2658*a(n-39) +93*a(n-40) -18*a(n-41) -a(n-42)
Showing 1-7 of 7 results.