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.

A251221 Number of (n+1) X (1+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

14, 49, 171, 597, 2084, 7275, 25396, 88654, 309479, 1080349, 3771351, 13165272, 45958169, 160433700, 560052166, 1955065729, 6824867819, 23824682749, 83168718156, 290330652147, 1013504710004, 3538006716150, 12350698916311
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 1 of A251228.

Examples

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

Crossrefs

Cf. A251228.

Formula

Empirical: a(n) = 3*a(n-1) + 2*a(n-2) - a(n-3).
Empirical g.f.: x*(14 + 7*x - 4*x^2) / (1 - 3*x - 2*x^2 + x^3). - Colin Barker, Feb 25 2018

A251220 Number of (n+1) X (n+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

14, 305, 20782, 4462968, 3007738372, 6373427948731, 42432102644410392, 887822645668106069016, 58374742677350528694024651, 12061621459257582136492647314788, 7831831916823870434473136772446378463
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Diagonal of A251228.

Examples

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

Crossrefs

Cf. A251228.

A251222 Number of (n+1) X (2+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

49, 305, 1892, 11753, 72985, 453273, 2814985, 17482154, 108570830, 674266427, 4187452312, 26005680486, 161505221644, 1003009195172, 6229070707553, 38684911434209, 240248095245952, 1492032555580773, 9266092805568853
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Examples

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

Crossrefs

Column 2 of A251228.

Formula

Empirical: a(n) = 5*a(n-1) + 9*a(n-2) - 8*a(n-3) - 8*a(n-4) + 3*a(n-5).
Empirical g.f.: x*(49 + 60*x - 74*x^2 - 60*x^3 + 24*x^4) / ((1 - x)*(1 + x)*(1 - 5*x - 8*x^2 + 3*x^3)). - Colin Barker, Nov 27 2018

A251223 Number of (n+1)X(3+1) 0..1 arrays with no 2X2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

171, 1892, 20782, 228689, 2515011, 27662994, 304255924, 3346446223, 36806732398, 404828461391, 4452610577279, 48973192395914, 538644351143299, 5924419545393448, 65161264266944558, 716693058210959682
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 3 of A251228

Examples

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

Formula

Empirical: a(n) = 8*a(n-1) +39*a(n-2) -48*a(n-3) -210*a(n-4) +88*a(n-5) +260*a(n-6) -199*a(n-7) +36*a(n-8)

A251224 Number of (n+1)X(4+1) 0..1 arrays with no 2X2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

597, 11753, 228689, 4462968, 87024544, 1697323707, 33102432698, 645599385182, 12591115117932, 245564664777825, 4789248769819459, 93404749891139903, 1821673395009104814, 35528107366814113243, 692904893934316841530
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 4 of A251228

Examples

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

Formula

Empirical: a(n) = 13*a(n-1) +150*a(n-2) -269*a(n-3) -3713*a(n-4) +1325*a(n-5) +30575*a(n-6) -16105*a(n-7) -99760*a(n-8) +117265*a(n-9) +20076*a(n-10) -71217*a(n-11) +11160*a(n-12) +14210*a(n-13) -3935*a(n-14) -1079*a(n-15) +396*a(n-16) +60*a(n-17)

A251225 Number of (n+1)X(5+1) 0..1 arrays with no 2X2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

2084, 72985, 2515011, 87024544, 3007738372, 103986727042, 3594807908974, 124275144041759, 4296252165879236, 148523812761431640, 5134547519926425245, 177504075991625903000, 6136411350172751480986, 212139042310887309043390
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 5 of A251228

Examples

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

Formula

Empirical: a(n) = 21*a(n-1) +554*a(n-2) -1341*a(n-3) -56723*a(n-4) -7614*a(n-5) +2277951*a(n-6) +445571*a(n-7) -46434220*a(n-8) +32482888*a(n-9) +467723527*a(n-10) -889155765*a(n-11) -1188153000*a(n-12) +4147652079*a(n-13) -132672964*a(n-14) -8042725671*a(n-15) +4499239992*a(n-16) +7457116236*a(n-17) -6933658033*a(n-18) -3126154333*a(n-19) +4558838720*a(n-20) +384337441*a(n-21) -1441277326*a(n-22) +61108155*a(n-23) +221926922*a(n-24) -13300621*a(n-25) -18641195*a(n-26) -491525*a(n-27) +335825*a(n-28) +5625*a(n-29)

A251226 Number of (n+1) X (6+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

7275, 453273, 27662994, 1697323707, 103986727042, 6373427948731, 390586327228567, 23937316421928928, 1466999236798838668, 89905332249468711934, 5509861728752949673273, 337672768681288148069329
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 6 of A251228.

Examples

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

Crossrefs

Cf. A251228.

Formula

Empirical recurrence of order 54 (see link above).

A251227 Number of (n+1)X(7+1) 0..1 arrays with no 2X2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

Original entry on oeis.org

25396, 2814985, 304255924, 33102432698, 3594807908974, 390586327228567, 42432102644410392, 4609884118941107106, 500818517947942768226, 54409178269320447394874, 5911035284990253460656387
Offset: 1

Views

Author

R. H. Hardin, Nov 30 2014

Keywords

Comments

Column 7 of A251228

Examples

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

Formula

Empirical recurrence of order 99 (see link above)
Showing 1-8 of 8 results.