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 1-5 of 5 results.

A219498 Number of n X 4 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 4 array.

Original entry on oeis.org

4, 7, 18, 35, 58, 88, 126, 173, 230, 298, 378, 471, 578, 700, 838, 993, 1166, 1358, 1570, 1803, 2058, 2336, 2638, 2965, 3318, 3698, 4106, 4543, 5010, 5508, 6038, 6601, 7198, 7830, 8498, 9203, 9946, 10728, 11550, 12413, 13318, 14266, 15258, 16295, 17378
Offset: 1

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Author

R. H. Hardin, Nov 20 2012

Keywords

Comments

Column 4 of A219502.

Examples

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

Crossrefs

Cf. A219502.

Formula

Empirical: a(n) = (1/6)*n^3 + 1*n^2 + (23/6)*n - 7 for n>2.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(4 - 9*x + 14*x^2 - 11*x^3 + 2*x^4 + x^5) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>6.
(End)

A219499 Number of n X 5 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 5 array.

Original entry on oeis.org

5, 9, 26, 58, 107, 179, 281, 421, 608, 852, 1164, 1556, 2041, 2633, 3347, 4199, 5206, 6386, 7758, 9342, 11159, 13231, 15581, 18233, 21212, 24544, 28256, 32376, 36933, 41957, 47479, 53531, 60146, 67358, 75202, 83714, 92931, 102891, 113633, 125197
Offset: 1

Views

Author

R. H. Hardin, Nov 20 2012

Keywords

Comments

Column 5 of A219502.

Examples

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

Crossrefs

Cf. A219502.

Formula

Empirical: a(n) = (1/24)*n^4 + (1/4)*n^3 + (35/24)*n^2 + (21/4)*n - 13 for n>2.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(5 - 16*x + 31*x^2 - 32*x^3 + 12*x^4 + 4*x^5 - 3*x^6) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>7.
(End)

A219500 Number of n X 6 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 6 array.

Original entry on oeis.org

6, 11, 35, 88, 179, 325, 550, 885, 1369, 2050, 2986, 4246, 5911, 8075, 10846, 14347, 18717, 24112, 30706, 38692, 48283, 59713, 73238, 89137, 107713, 129294, 154234, 182914, 215743, 253159, 295630, 343655, 397765, 458524, 526530, 602416, 686851
Offset: 1

Views

Author

R. H. Hardin, Nov 20 2012

Keywords

Comments

Column 6 of A219502.

Examples

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

Crossrefs

Cf. A219502.

Formula

Empirical: a(n) = (1/120)*n^5 + (1/24)*n^4 + (13/24)*n^3 + (59/24)*n^2 + (59/20)*n - 17 for n>3.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(6 - 25*x + 59*x^2 - 77*x^3 + 46*x^4 - 10*x^6 + x^7 + x^8) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>9.
(End)

A219497 Number of n X n arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X n array.

Original entry on oeis.org

2, 3, 11, 35, 107, 325, 995, 3083, 9663, 30581, 97541
Offset: 1

Views

Author

R. H. Hardin Nov 20 2012

Keywords

Comments

Diagonal of A219502

Examples

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

A219501 Number of n X 7 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 7 array.

Original entry on oeis.org

7, 13, 45, 126, 281, 550, 995, 1703, 2793, 4424, 6804, 10200, 14949, 21470, 30277, 41993, 57365, 77280, 102782, 135090, 175617, 225990, 288071, 363979, 456113, 567176, 700200, 858572, 1046061, 1266846, 1525545, 1827245, 2177533, 2582528
Offset: 1

Views

Author

R. H. Hardin, Nov 20 2012

Keywords

Comments

Column 7 of A219502.

Examples

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

Crossrefs

Cf. A219502.

Formula

Empirical: a(n) = (1/720)*n^6 + (1/240)*n^5 + (23/144)*n^4 + (13/16)*n^3 + (331/180)*n^2 + (311/60)*n - 27 for n>3.
Showing 1-5 of 5 results.