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 1-7 of 7 results.

A223764 Number of n X 2 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

4, 12, 28, 56, 101, 169, 267, 403, 586, 826, 1134, 1522, 2003, 2591, 3301, 4149, 5152, 6328, 7696, 9276, 11089, 13157, 15503, 18151, 21126, 24454, 28162, 32278, 36831, 41851, 47369, 53417, 60028, 67236, 75076, 83584, 92797, 102753, 113491, 125051
Offset: 1

Views

Author

R. H. Hardin, Mar 27 2013

Keywords

Comments

Column 2 of A223770.

Examples

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

Crossrefs

Cf. A223770.

Formula

Empirical: a(n) = (1/24)*n^4 + (1/4)*n^3 + (35/24)*n^2 + (5/4)*n + 1.
Conjectures from Colin Barker, Feb 21 2018: (Start)
G.f.: x*(2 - 2*x + x^2)^2 / (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>5.
(End)

A223765 Number of n X 3 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

7, 28, 71, 155, 317, 607, 1097, 1887, 3112, 4950, 7631, 11447, 16763, 24029, 33793, 46715, 63582, 85324, 113031, 147971, 191609, 245627, 311945, 392743, 490484, 607938, 748207, 914751, 1111415, 1342457, 1612577, 1926947, 2291242, 2711672
Offset: 1

Views

Author

R. H. Hardin, Mar 27 2013

Keywords

Comments

Column 3 of A223770.

Examples

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

Crossrefs

Cf. A223770.

Formula

Empirical: a(n) = (1/720)*n^6 + (1/240)*n^5 + (41/144)*n^4 - (13/48)*n^3 + (2237/360)*n^2 - (217/30)*n + 19 for n>2.
Conjectures from Colin Barker, Aug 22 2018: (Start)
G.f.: x*(7 - 21*x + 22*x^2 + x^3 - 12*x^4 - 9*x^5 + 26*x^6 - 17*x^7 + 4*x^8) / (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>9.
(End)

A223766 Number of n X 4 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

11, 56, 155, 361, 782, 1601, 3141, 5907, 10678, 18618, 31422, 51505, 82243, 128276, 195884, 293448, 432009, 625939, 893739, 1258980, 1751404, 2408203, 3275495, 4410017, 5881056, 7772640, 10186012, 13242411, 17086185, 21888262, 27850006
Offset: 1

Views

Author

R. H. Hardin, Mar 27 2013

Keywords

Comments

Column 4 of A223770.

Examples

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

Crossrefs

Cf. A223770.

Formula

Empirical: a(n) = (1/40320)*n^8 - (1/10080)*n^7 + (3/320)*n^6 + (1/45)*n^5 + (1109/1920)*n^4 - (4837/1440)*n^3 + (422483/10080)*n^2 - (109337/840)*n + 226 for n>4.
Conjectures from Colin Barker, Aug 22 2018: (Start)
G.f.: x*(11 - 43*x + 47*x^2 + 58*x^3 - 205*x^4 + 209*x^5 - 42*x^6 - 150*x^7 + 256*x^8 - 245*x^9 + 151*x^10 - 55*x^11 + 9*x^12) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>13.
(End)

A223767 Number of nX5 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

16, 101, 317, 782, 1748, 3699, 7564, 14980, 28778, 53619, 96979, 170525, 292045, 488120, 797778, 1277432, 2007477, 3101006, 4715203, 7066083, 10447376, 15254495, 22014688, 31424652, 44397084, 62117861, 86115779, 118347041, 161296967
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Column 5 of A223770

Examples

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

Formula

Empirical: a(n) = (1/3628800)*n^10 - (1/241920)*n^9 + (23/120960)*n^8 - (43/40320)*n^7 + (11293/172800)*n^6 - (1721/2304)*n^5 + (1557823/181440)*n^4 - (3058823/60480)*n^3 + (99347/350)*n^2 - (196177/210)*n + 1664 for n>6

A223768 Number of nX6 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

22, 169, 607, 1601, 3699, 8007, 16742, 34096, 67890, 132115, 251110, 465910, 843960, 1493505, 2584666, 4379914, 7277630, 11873716, 19047873, 30083272, 46831011, 71934087, 109129744, 163654129, 242779358, 356520541, 518559236, 747440414
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Column 6 of A223770

Examples

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

Formula

Empirical: a(n) = (1/479001600)*n^12 - (1/15966720)*n^11 + (23/8709120)*n^10 - (59/1451520)*n^9 + (22591/14515200)*n^8 - (1159/53760)*n^7 + (713737/1741824)*n^6 - (1665749/290304)*n^5 + (795178259/10886400)*n^4 - (220668799/362880)*n^3 + (73774259/20790)*n^2 - (340682581/27720)*n + 20228 for n>8

A223769 Number of nX7 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

29, 267, 1097, 3141, 7564, 16742, 35513, 73427, 149053, 297518, 583860, 1125118, 2126567, 3939287, 7150127, 12719513, 22189580, 37994506, 63918056, 105761409, 172308985, 276713314, 438464653, 686170386, 1061447357, 1624332246
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Column 7 of A223770

Examples

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

Formula

Empirical: a(n) = (1/87178291200)*n^14 - (1/1779148800)*n^13 + (1/38320128)*n^12 - (127/191600640)*n^11 + (311/12441600)*n^10 - (2021/3225600)*n^9 + (2304587/121927680)*n^8 - (6921119/17418240)*n^7 + (278861369/43545600)*n^6 - (1599083081/21772800)*n^5 + (2209531079/3421440)*n^4 - (4215012997/997920)*n^3 + (3157078175059/151351200)*n^2 - (25129653953/360360)*n + 120027 for n>10

A223763 Number of n X n 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

Original entry on oeis.org

2, 12, 71, 361, 1748, 8007, 35513, 153450, 651075, 2723829, 11275932, 46302339, 188958191, 767474182, 3105857015
Offset: 1

Views

Author

R. H. Hardin Mar 27 2013

Keywords

Comments

Diagonal of A223770

Examples

			Some solutions for n=3
..0..0..0....0..0..0....1..1..1....1..0..0....0..0..0....1..1..1....0..0..1
..0..0..0....0..1..1....1..1..1....0..1..0....0..1..1....0..1..1....0..0..0
..0..0..1....0..1..1....0..1..1....0..1..1....0..0..1....0..1..1....0..0..0
		
Showing 1-7 of 7 results.