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 13 results. Next

A268992 Number of nX5 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

23, 278, 3331, 37987, 421450, 4583103, 49084071, 519385102, 5442503771, 56571775611, 584048456162, 5994862809815, 61225907059807, 622579765715526, 6306473266306611, 63664757730483923, 640753995659371194
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 5 of A268995.

Examples

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

Crossrefs

Cf. A268995.

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

A268988 Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

2, 13, 174, 6009, 421450, 66954420, 22995344760, 17373640598542, 29082748697180602, 107300241515211644436, 883523091936988991189604, 16140842052133986432421342048, 659806253617230823177640504040304
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Diagonal of A268995.

Examples

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

Crossrefs

Cf. A268995.

A268989 Number of n X 2 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

4, 13, 41, 126, 379, 1121, 3272, 9449, 27049, 76866, 217079, 609793, 1705036, 4748101, 13174889, 36440646, 100503667, 276476129, 758785424, 2078056481, 5680052329, 15497929098, 42216552431, 114824352001, 311871557524
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Column 2 of A268995.

Formula

Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4).
Empirical g.f.: x*(4 - 11*x + 7*x^2 - x^3) / (1 - 3*x + x^2)^2. - Colin Barker, Jan 17 2019

A268990 Number of n X 3 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

7, 35, 174, 849, 4083, 19416, 91491, 427863, 1988142, 9187653, 42256599, 193542240, 883204143, 4017241083, 18219040206, 82410172617, 371879874987, 1674499435176, 7525052043819, 33755742643791, 151168877259918, 675941817039645
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Column 3 of A268995.

Formula

Empirical: a(n) = 10*a(n-1) - 31*a(n-2) + 30*a(n-3) - 9*a(n-4).
Empirical g.f.: x*(7 - 35*x + 41*x^2 - 16*x^3) / (1 - 5*x + 3*x^2)^2. - Colin Barker, Jan 17 2019

A268991 Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

13, 103, 805, 6009, 43512, 308112, 2144780, 14730784, 100087792, 674045392, 4505925696, 29933341056, 197782652096, 1300744853760, 8519586895104, 55600022810880, 361688403251200, 2346083095244800, 15178387509332992
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Column 4 of A268995.

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*(13 - 105*x + 301*x^2 - 407*x^3 + 312*x^4 - 112*x^5 + 4*x^6) / (1 - 8*x + 12*x^2 - 4*x^3)^2. - Colin Barker, Jan 17 2019

A268993 Number of nX6 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

41, 763, 14080, 244397, 4097199, 66954420, 1073436321, 16957258387, 264744926212, 4093941136805, 62806688095479, 957111538353668, 14502245681077257, 218656000387543867, 3282569954305098964
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 6 of A268995.

Examples

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

Crossrefs

Cf. A268995.

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

A268994 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

72, 2037, 57287, 1506570, 38241770, 946498448, 22995344760, 550731432312, 13040291111728, 305911647779632, 7121104059933536, 164688437285444064, 3787495455529375808, 86684333527271203264, 1975573336154420926848
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Column 7 of A268995.

Examples

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

Crossrefs

Cf. A268995.

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

A268996 Number of 2 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

4, 13, 35, 103, 278, 763, 2037, 5421, 14264, 37321, 97015, 250963, 646250, 1657719, 4237481, 10798553, 27442092, 69563653, 175938699, 444060607, 1118668286, 2813233523, 7063416349, 17708464645, 44335423456, 110857865665, 276863340767
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Row 2 of A268995.

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*(4 + 5*x - 11*x^2 - 16*x^3 - 7*x^4 - x^5) / ((1 + x)^2*(1 - 2*x - x^2)^2). - Colin Barker, Jan 18 2019

A268997 Number of 3 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

8, 41, 174, 805, 3331, 14080, 57287, 232449, 928886, 3688159, 14524152, 56872865, 221485093, 858684462, 3315594029, 12757162785, 48929395140, 187135343189, 713890088738, 2717075148077, 10319450344743, 39117842242220
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Examples

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

Crossrefs

Row 3 of A268995.

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*(8 + 17*x - 45*x^2 - 81*x^3 - 20*x^4 + 25*x^5 + 9*x^6 - 2*x^7 - x^8) / ((1 + x)*(1 - 2*x - 6*x^2 + x^4)^2). - Colin Barker, Jan 18 2019

A268998 Number of 4Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

16, 126, 849, 6009, 37987, 244397, 1506570, 9258784, 55904997, 335264275, 1991983545, 11763490813, 69051103048, 403375829894, 2346089237885, 13593697842329, 78497992061491, 451930855824889, 2594820580805818
Offset: 1

Views

Author

R. H. Hardin, Feb 17 2016

Keywords

Comments

Row 4 of A268995.

Examples

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

Crossrefs

Cf. A268995.

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)
Showing 1-10 of 13 results. Next