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 1-8 of 8 results.

A202882 Number of n X 1 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

1, 3, 9, 22, 51, 121, 292, 704, 1691, 4059, 9749, 23422, 56268, 135166, 324692, 779977, 1873673, 4500958, 10812237, 25973244, 62393157, 149881402, 360046432, 864906711, 2077686532, 4991036946, 11989513056, 28801314179, 69186771332
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=5
..2....2....1....0....2....2....0....1....0....1....1....0....2....1....0....2
..2....2....1....1....2....2....2....1....2....2....1....0....2....2....1....2
..0....1....1....2....0....2....2....0....2....2....1....1....1....2....1....0
..0....1....1....2....1....1....2....0....0....0....2....1....2....2....2....2
..0....0....1....2....1....1....1....0....0....0....2....1....2....0....2....2
		

Crossrefs

Column 1 of A202889.

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +4*a(n-3) -a(n-4) +a(n-5).
Empirical: G.f.: -x*(1+3*x^2+x^4)/(-1+3*x-3*x^2+4*x^3-x^4+x^5). - R. J. Mathar, Jul 09 2017

A202883 Number of n X 2 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

3, 35, 265, 1849, 13345, 96941, 701275, 5071167, 36689027, 265439091, 1920308033, 13892446697, 100505282121, 727107537885, 5260271847715, 38055531396239, 275313438949691, 1991760080088995, 14409424470217081, 104245243244589977
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Comments

Column 2 of A202889.

Examples

			Some solutions for n=5:
  2 0   2 1   2 0   0 0   0 0   0 1   2 2   2 1   1 2   2 2
  2 0   2 1   2 2   1 1   0 2   2 2   2 1   2 2   1 2   1 1
  0 2   2 1   2 2   1 0   0 2   0 1   0 0   2 0   1 2   2 1
  0 2   2 0   0 0   2 1   2 2   1 1   2 0   0 1   2 2   2 0
  0 1   1 0   1 1   2 1   2 1   2 2   2 1   1 1   0 1   1 0
		

Crossrefs

Cf. A202889.

Formula

Empirical: a(n) = 6*a(n-1) +2*a(n-2) +46*a(n-3) +25*a(n-4) +36*a(n-5).
Empirical g.f.: (3 + 17*x + 49*x^2 + 51*x^3 + 36*x^4) / (1 - 6*x - 2*x^2 - 46*x^3 - 25*x^4 - 36*x^5). - Colin Barker, Jun 02 2018

A202884 Number of nX3 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

9, 265, 5493, 109119, 2223723, 45332961, 922352267, 18770352883, 382034229103, 7775324294349, 158245814846079, 3220677883878199, 65548442623908105, 1334066131775449299, 27151407675046583355, 552595506856781602893
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=3
..1..1..1....1..2..2....0..0..2....0..2..2....2..1..1....1..0..0....0..0..2
..1..0..2....1..2..1....0..1..2....0..1..1....2..1..0....2..2..2....2..2..2
..1..2..2....0..2..0....0..2..2....2..2..1....1..1..0....2..1..1....0..2..2
		

Crossrefs

Column 3 of A202889.

Formula

Empirical: a(n) = 22*a(n-1) -73*a(n-2) +857*a(n-3) -1769*a(n-4) +12671*a(n-5) +21249*a(n-6) +11663*a(n-7) -43772*a(n-8) -233931*a(n-9) -841906*a(n-10) -520038*a(n-11) -711742*a(n-12) +722084*a(n-13) +4070420*a(n-14) +788112*a(n-15) -3390432*a(n-16) -1162224*a(n-17) +645120*a(n-18) +248832*a(n-19)

A202885 Number of nX4 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

22, 1849, 109119, 6092872, 348151747, 19914296913, 1137589582096, 64992189188797, 3713325091122745, 212156302986486914, 12121270553957772787, 692534079965581463725, 39567093279061401381682, 2260617527909089482464661
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=2
..0..2..2..0....2..0..2..2....0..0..1..1....2..2..0..0....1..2..1..1
..0..0..1..0....2..1..1..1....0..0..1..1....1..1..1..0....0..2..0..1
		

Crossrefs

Column 4 of A202889.

Formula

Empirical: a(n) = 58*a(n-1) -409*a(n-2) +19812*a(n-3) -7455*a(n-4) +2592909*a(n-5) +12335100*a(n-6) -16921246*a(n-7) -80782159*a(n-8) -4256903692*a(n-9) -15824503819*a(n-10) +51444732070*a(n-11) +665973079452*a(n-12) +1722193958142*a(n-13) -9381699323187*a(n-14) -52231180624458*a(n-15) -96373950069860*a(n-16) +536481249758489*a(n-17) +2646445223858022*a(n-18) -2670449971660545*a(n-19) -23685322388362288*a(n-20) +5273037676253028*a(n-21) +123562120872374900*a(n-22) +14554488540108224*a(n-23) -423772107328693168*a(n-24) -137361850647059616*a(n-25) +951983290636001856*a(n-26) +456183082446901248*a(n-27) -1309658113153668096*a(n-28) -798409204703133696*a(n-29) +997927647389908992*a(n-30) +720498553714114560*a(n-31) -407490029986775040*a(n-32) -334751276287918080*a(n-33) +70526354545704960*a(n-34) +67405719388815360*a(n-35)

A202886 Number of nX5 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

51, 13345, 2223723, 348151747, 56006562037, 9024909392725, 1452080571954205, 233641209300452607, 37595413242729744773, 6049464276674659581373, 973416350404566342317495, 156632059367518718442398187
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=2
..2..2..1..2..2....1..0..0..2..2....1..2..2..1..0....1..1..1..2..0
..1..1..1..0..2....2..2..0..0..1....0..1..2..0..0....0..2..2..2..1
		

Crossrefs

Column 5 of A202889.

A202887 Number of nX6 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

121, 96941, 45332961, 19914296913, 9024909392725, 4095290003129296, 1855037301620277541, 840314045399310110892, 380686256792369384392819, 172460622525800448862240139, 78128840457226148615810468318
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=2
..1..2..2..0..2..2....1..0..1..1..2..2....1..2..1..1..2..2....1..1..1..0..0..0
..0..0..1..0..1..2....1..1..0..0..0..1....0..2..2..0..0..2....0..2..2..0..2..2
		

Crossrefs

Column 6 of A202889.

A202888 Number of nX7 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

292, 701275, 922352267, 1137589582096, 1452080571954205, 1855037301620277541, 2365289879500027706428, 3016217753359820252116493, 3846628606342304091797101743, 4905606162973199116333144693744
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=2
..0..0..0..1..1..0..2....0..1..1..2..1..1..0....0..0..2..2..0..2..2
..0..1..1..0..1..2..2....0..0..0..2..0..1..0....0..1..2..2..0..1..2
		

Crossrefs

Column 7 of A202889.

A202881 Number of n X n 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.

Original entry on oeis.org

1, 35, 5493, 6092872, 56006562037, 4095290003129296, 2365289879500027706428, 10827985400073310953152590562, 392915439811314078675718437985175633, 112991429416970014192131075985467073204579858
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2011

Keywords

Examples

			Some solutions for n=3
..1..2..2....0..1..1....0..2..1....2..1..2....2..2..0....2..2..1....0..1..0
..1..1..1....0..2..0....1..2..2....2..2..2....2..2..1....2..1..0....1..2..0
..0..1..0....1..2..2....1..1..0....2..2..1....0..0..1....0..1..1....1..2..1
		

Crossrefs

Diagonal of A202889.
Showing 1-8 of 8 results.