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 11 results. Next

A266423 Number of n X 3 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

4, 14, 39, 96, 212, 433, 826, 1493, 2575, 4270, 6841, 10639, 16114, 23845, 34555, 49147, 68725, 94637, 128501, 172257, 228199, 299035, 387927, 498560, 635189, 802719, 1006760, 1253717, 1550855, 1906400, 2329613, 2830904, 3421916, 4115651
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Examples

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

Crossrefs

Column 3 of A266428.

Formula

Empirical: a(n) = 5*a(n-1) - 8*a(n-2) + a(n-3) + 9*a(n-4) - 6*a(n-5) - 6*a(n-7) + 9*a(n-8) + a(n-9) - 8*a(n-10) + 5*a(n-11) - a(n-12).
Empirical g.f.: x*(4 - 6*x + x^2 + 9*x^3 - 6*x^4 - 6*x^6 + 9*x^7 + x^8 - 8*x^9 + 5*x^10 - x^11) / ((1 - x)^8*(1 + x)^2*(1 + x + x^2)). - Colin Barker, Jan 09 2019

A266424 Number of nX4 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

5, 25, 106, 404, 1391, 4383, 12758, 34611, 88206, 212609, 487630, 1069664, 2254259, 4581719, 9011222, 17200214, 31944220, 57853902, 102380657, 177341666, 301156443, 502075951, 822789263, 1326908069, 2107999291, 3302022425
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Column 4 of A266428.

Examples

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

Crossrefs

Cf. A266428.

A266425 Number of nX5 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

6, 41, 259, 1556, 8764, 45907, 223075, 1005991, 4224203, 16588684, 61226525, 213418690, 705807396, 2223963956, 6702140026, 19383434369, 53965133477, 145029252226, 377163396856, 951257706522, 2331468492530, 5562985385965
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Column 5 of A266428.

Examples

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

Crossrefs

Cf. A266428.

A266429 Number of 3 X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

4, 13, 39, 106, 259, 574, 1170, 2223, 3982, 6787, 11089, 17472, 26677, 39628, 57460, 81549, 113544, 155401, 209419, 278278, 365079, 473386, 607270, 771355, 970866, 1211679, 1500373, 1844284, 2251561, 2731224, 3293224, 3948505, 4709068, 5588037
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Examples

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

Crossrefs

Row 3 of A266428.

Formula

Empirical: a(n) = (1/360)*n^6 + (1/40)*n^5 + (1/9)*n^4 + (7/24)*n^3 + (319/360)*n^2 + (101/60)*n + 1.
Conjectures from Colin Barker, Jan 09 2019: (Start)
G.f.: x*(4 - 15*x + 32*x^2 - 34*x^3 + 21*x^4 - 7*x^5 + x^6) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.
(End)

A266430 Number of 4 X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

5, 22, 96, 404, 1556, 5365, 16585, 46463, 119452, 285124, 638247, 1351194, 2724385, 5262379, 9785590, 17590461, 30674359, 52045522, 86143170, 139398464, 220973442, 343722465, 525429159, 790381435, 1171358006, 1712112000, 2470450897
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Examples

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

Crossrefs

Row 4 of A266428.

Formula

Empirical: a(n) = (1/9979200)*n^11 + (1/201600)*n^10 + (1/12096)*n^9 + (1/1344)*n^8 + (1271/302400)*n^7 + (479/28800)*n^6 + (12797/181440)*n^5 + (97/504)*n^4 + (1779/2800)*n^3 + (2032/1575)*n^2 + (8269/4620)*n + 1.
Conjectures from Colin Barker, Jan 09 2019: (Start)
G.f.: x*(5 - 38*x + 162*x^2 - 396*x^3 + 679*x^4 - 833*x^5 + 737*x^6 - 471*x^7 + 213*x^8 - 65*x^9 + 12*x^10 - x^11) / (1 - x)^12.
a(n) = 12*a(n-1) - 66*a(n-2) + 220*a(n-3) - 495*a(n-4) + 792*a(n-5) - 924*a(n-6) + 792*a(n-7) - 495*a(n-8) + 220*a(n-9) - 66*a(n-10) + 12*a(n-11) - a(n-12) for n>12.
(End)

A266431 Number of 5Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

6, 34, 212, 1391, 8764, 49894, 251381, 1122721, 4490732, 16284683, 54165714, 166968275, 481237398, 1306708520, 3364174219, 8257222586, 19412425379, 43890267973, 95767324137, 202278568268, 414691101885, 827108931171
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Row 5 of A266428.

Examples

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

Crossrefs

Cf. A266428.

Formula

Empirical: a(n) = (1/7602818775552000)*n^19 + (1/47076277248000)*n^18 + (389/266765571072000)*n^17 + (47/815173632000)*n^16 + (11629/7846046208000)*n^15 + (413249/15692092416000)*n^14 + (7941701/23538138624000)*n^13 + (23266079/7242504192000)*n^12 + (14091433/603542016000)*n^11 + (267047/1959552000)*n^10 + (794703337/1207084032000)*n^9 + (14650018639/4828336128000)*n^8 + (267287875667/23538138624000)*n^7 + (102484112767/2139830784000)*n^6 + (39001810891/326918592000)*n^5 + (73310538271/186810624000)*n^4 + (87546462023/102918816000)*n^3 + (113077535/72648576)*n^2 + (469781209/232792560)*n + 1

A266432 Number of 6Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

7, 50, 433, 4383, 45907, 448649, 3889553, 29520031, 197001842, 1168481498, 6234449897, 30265682491, 135048855227, 558800630541, 2160517610564, 7856777499625, 27025799141430, 88367939113010, 275837411169430
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Row 6 of A266428.

Examples

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

Crossrefs

Cf. A266428.

Formula

Empirical polynomial of degree 33 (see link above)

A266433 Number of 7Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

8, 70, 826, 12758, 223075, 3825307, 59155748, 798834778, 9379683461, 96481143688, 879275711012, 7183343579974, 53182973236784, 360298764101463, 2252503422916387, 13090825673375302, 71176326297105679, 364068218093477268
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Row 7 of A266428.

Examples

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

Crossrefs

Cf. A266428.

Formula

Empirical polynomial of degree 57 (see link above)

A266422 Number of n X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

2, 7, 39, 404, 8764, 448649, 59155748, 21325003746, 21901867532457, 66087854484252677, 600640567173169508177
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Diagonal of A266428.

Examples

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

Crossrefs

Cf. A266428.

A266426 Number of nX6 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

Original entry on oeis.org

7, 63, 574, 5365, 49894, 448649, 3825307, 30555624, 227542455, 1579153474, 10236107278, 62184207773, 355425984636, 1918894455423, 9822580592133, 47841257692021, 222427734697477, 990076818618586
Offset: 1

Views

Author

R. H. Hardin, Dec 29 2015

Keywords

Comments

Column 6 of A266428.

Examples

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

Crossrefs

Cf. A266428.
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