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 10 results.

A180762 Half the number of nX2 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

1, 3, 11, 34, 111, 361, 1172, 3809, 12377, 40218, 130687, 424661, 1379916, 4483973, 14570461, 47346034, 153848731, 499924281, 1624480652, 5278674169, 17152805697, 55737242698, 181115572487, 588526611821, 1912389796556, 6214221516093
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 2 of A180771

Formula

Empirical: a(n) = 3*a(n-1) + a(n-2) - 2*a(n-4).
Empirical g.f.: x*(1-x)*(1+x+2*x^2)/(1-3*x-x^2+2*x^4). - Colin Barker, Feb 22 2012

A180763 Half the number of n X 3 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

1, 11, 63, 390, 2385, 14621, 89602, 549125, 3365327, 20624430, 126397089, 774626021, 4747304792, 29093913597, 178302394173, 1092728334730, 6696798543441, 41041409200977, 251522762447718, 1541460229095645
Offset: 1

Views

Author

R. H. Hardin, Sep 20 2010

Keywords

Comments

Column 3 of A180771.

Crossrefs

Cf. A180771.

Formula

Empirical: a(n) = 5*a(n-1) + 8*a(n-2) - 5*a(n-3) - 10*a(n-4) - a(n-5) + 3*a(n-6) + 4*a(n-7) - 2*a(n-8).
Empirical g.f.: x*(1 - x)*(1 + 7*x + 7*x^2 - x^3 - 5*x^4 - 3*x^5 + 2*x^6) / (1 - 5*x - 8*x^2 + 5*x^3 + 10*x^4 + x^5 - 3*x^6 - 4*x^7 + 2*x^8). - Colin Barker, Mar 26 2018

A180764 Half the number of nX4 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

2, 34, 390, 4475, 52186, 606546, 7053923, 82032712, 953982820, 11094190209, 129018028226, 1500393683522, 17448578663219, 202915341402216, 2359770191311572, 27442554696574793, 319138622503858354
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 4 of A180771

Formula

Empirical: a(n) = 9*a(n-1) + 35*a(n-2) - 29*a(n-3) - 256*a(n-4) - 120*a(n-5) + 695*a(n-6) + 579*a(n-7) - 949*a(n-8) - 1076*a(n-9) + 485*a(n-10) + 1488*a(n-11) + 588*a(n-12) - 857*a(n-13) - 368*a(n-14) - 73*a(n-15) - 52*a(n-16) + 26*a(n-17) + 14*a(n-18) + 12*a(n-19) - 4*a(n-20)

A180765 Half the number of nX5 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

3, 111, 2385, 52186, 1154119, 25448809, 561487456, 12387396391, 273289411333, 6029284136868, 133017439433103, 2934617106201383, 64743220889823228, 1428358285117311045, 31512293679807784965, 695220984328633501278
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 5 of A180771

Formula

Empirical: a(n) = 17*a(n-1) + 136*a(n-2) - 345*a(n-3) - 4373*a(n-4) + 71*a(n-5) + 66879*a(n-6) + 73663*a(n-7) - 605750*a(n-8) - 1149380*a(n-9) + 3440076*a(n-10) + 9495118*a(n-11) - 11523196*a(n-12) - 49881727*a(n-13) + 14883216*a(n-14) + 170573727*a(n-15) + 56476212*a(n-16) - 384039937*a(n-17) - 365812542*a(n-18) + 600541982*a(n-19) + 912782329*a(n-20) - 647992787*a(n-21) - 1217873627*a(n-22) + 831099316*a(n-23) + 509861969*a(n-24) - 535317645*a(n-25) - 243113473*a(n-26) + 146477582*a(n-27) + 239475023*a(n-28) - 56646215*a(n-29) - 153066695*a(n-30) + 13721643*a(n-31) + 55901473*a(n-32) + 8739700*a(n-33) - 17235985*a(n-34) - 7556526*a(n-35) + 4435220*a(n-36) + 2967912*a(n-37) - 742411*a(n-38) - 903018*a(n-39) + 68146*a(n-40) + 206458*a(n-41) + 20454*a(n-42) - 27768*a(n-43) - 10964*a(n-44) + 1696*a(n-45) + 1408*a(n-46)

A180766 Half the number of nX6 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

5, 361, 14621, 606546, 25448809, 1064583557, 44560487654, 1865051797753, 78060898850787, 3267207111743056, 136747572763258659, 5723512289789881283, 239555203487051506472, 10026482454922619039947, 419654213169799743389447
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 6 of A180771

A180767 Half the number of nX7 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

8, 1172, 89602, 7053923, 561487456, 44560487654, 3538520414645, 280971809714842, 22310318523546774, 1771532822371947357, 140667082973087038600, 11169552997132511054788, 886909077729036810872471
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 7 of A180771

A180768 Half the number of n X 8 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

13, 3809, 549125, 82032712, 12387396391, 1865051797753, 280971809714842, 42325704140613463, 6375989200126477033, 960486733026829603882, 144688833229486140773839, 21796094961106865613962841
Offset: 1

Views

Author

R. H. Hardin, Sep 20 2010

Keywords

Comments

Column 8 of A180771.

Crossrefs

Cf. A180771.

A180769 Half the number of nX9 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

21, 12377, 3365327, 953982820, 273289411333, 78060898850787, 22310318523546774, 6375989200126477033, 1822180205677117048273, 520757452730725828979262, 148826239836327503673819877
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 9 of A180771

A180770 Half the number of nX10 binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

34, 40218, 20624430, 11094190209, 6029284136868, 3267207111743056, 1771532822371947357, 960486733026829603882, 520757452730725828979262, 282344956970612464702333909, 153082103894376275149564128624
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Column 10 of A180771

A180761 Half the number of n X n binary arrays with each element equal to at least one neighbor.

Original entry on oeis.org

0, 3, 63, 4475, 1154119, 1064583557, 3538520414645, 42325704140613463, 1822180205677117048273, 282344956970612464702333909, 157459613671260527898784781898227
Offset: 1

Views

Author

R. H. Hardin Sep 20 2010

Keywords

Comments

Diagonal of A180771
Showing 1-10 of 10 results.