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.

A252814 Number of n X 2 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

2, 6, 17, 40, 81, 147, 246, 387, 580, 836, 1167, 1586, 2107, 2745, 3516, 4437, 5526, 6802, 8285, 9996, 11957, 14191, 16722, 19575, 22776, 26352, 30331, 34742, 39615, 44981, 50872, 57321, 64362, 72030, 80361, 89392, 99161, 109707, 121070, 133291
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Examples

			Some solutions for n=4:
..0..0....0..1....0..1....0..1....0..1....0..1....0..1....0..0....0..0....0..1
..0..1....0..1....1..2....1..2....0..1....0..1....1..2....1..1....1..1....1..2
..1..1....1..1....2..3....2..3....1..2....1..1....2..2....1..2....2..2....2..2
..2..2....1..2....2..3....3..4....2..2....2..2....3..3....1..2....2..3....2..2
		

Crossrefs

Column 2 of A252820.

Formula

Empirical: a(n) = (1/24)*n^4 + (5/12)*n^3 - (1/24)*n^2 + (7/12)*n + 1.
Conjectures from Colin Barker, Dec 06 2018: (Start)
G.f.: x*(2 - 4*x + 7*x^2 - 5*x^3 + x^4) / (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)

A252813 Number of n X n nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

1, 6, 63, 684, 7564, 86724, 1033761, 12755742, 161986236, 2106102800, 27918827562, 376114207132, 5136290930902, 70961672284626, 990271326335611, 13940676825684808, 197768062909075426, 2824828311338844486
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Comments

Diagonal of A252820

Examples

			Some solutions for n=4
..0..0..1..2....0..1..2..3....0..1..1..2....0..1..1..2....0..1..2..2
..0..0..1..2....1..1..2..3....0..1..1..2....1..2..2..3....1..2..2..3
..0..1..2..3....2..2..3..4....0..1..2..3....2..2..3..3....2..2..3..4
..1..2..3..4....2..3..4..4....1..2..3..4....2..3..3..4....3..3..4..5
		

A252815 Number of n X 3 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

4, 17, 63, 187, 468, 1032, 2067, 3840, 6716, 11179, 17855, 27537, 41212, 60090, 85635, 119598, 164052, 221429, 294559, 386711, 501636, 643612, 817491, 1028748, 1283532, 1588719, 1951967, 2381773, 2887532, 3479598, 4169347, 4969242, 5892900, 6955161
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Examples

			Some solutions for n=4:
..0..0..1....0..0..0....0..1..1....0..0..1....0..1..2....0..1..2....0..1..1
..0..0..1....1..1..1....1..2..2....1..1..2....1..2..2....1..2..3....0..1..1
..1..1..2....1..1..2....2..2..3....1..2..2....2..3..3....1..2..3....1..1..2
..1..2..3....2..2..3....2..3..4....1..2..3....2..3..3....1..2..3....2..2..3
		

Crossrefs

Column 3 of A252820.

Formula

Empirical: a(n) = (1/360)*n^6 + (1/20)*n^5 + (5/18)*n^4 + (1/2)*n^3 + (439/360)*n^2 - (1/20)*n + 2.
Conjectures from Colin Barker, Dec 06 2018: (Start)
G.f.: x*(4 - 11*x + 28*x^2 - 37*x^3 + 27*x^4 - 11*x^5 + 2*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)

A252816 Number of n X 4 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

7, 40, 187, 684, 2078, 5490, 13015, 28299, 57338, 109549, 199168, 347035, 582831, 947837, 1498290, 2309416, 3480225, 5139158, 7450681, 10622926, 14916484, 20654460, 28233905, 38138745, 50954332, 67383747, 88265990, 114596197
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Examples

			Some solutions for n=4:
..0..0..1..2....0..1..1..1....0..1..2..3....0..0..1..2....0..0..1..1
..1..1..2..3....0..1..1..2....1..2..3..3....1..1..1..2....1..1..1..2
..1..1..2..3....1..2..2..3....1..2..3..3....2..2..2..3....1..2..2..3
..1..2..3..4....1..2..3..4....2..3..3..4....2..3..3..4....1..2..3..4
		

Crossrefs

Column 4 of A252820.

Formula

Empirical: a(n) = (1/8064)*n^8 + (1/288)*n^7 + (103/2880)*n^6 + (17/90)*n^5 + (703/1152)*n^4 + (451/288)*n^3 + (2869/3360)*n^2 + (209/120)*n + 2.
Conjectures from Colin Barker, Dec 06 2018: (Start)
G.f.: x*(7 - 23*x + 79*x^2 - 147*x^3 + 176*x^4 - 138*x^5 + 67*x^6 - 18*x^7 + 2*x^8) / (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>9.
(End)

A252817 Number of n X 5 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

11, 81, 468, 2078, 7564, 23664, 65711, 165685, 385736, 839799, 1726761, 3379640, 6336411, 11439478, 19972358, 33843927, 55832593, 89905021, 141626554, 218683266, 331538662, 494251420, 725484265, 1049738089, 1498849798
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Examples

			Some solutions for n=4:
..0..1..1..2..3....0..1..2..3..3....0..1..1..2..3....0..0..1..2..3
..1..2..2..3..3....1..2..2..3..4....1..1..2..3..4....1..1..2..3..4
..2..3..3..4..4....2..2..2..3..4....1..2..3..4..4....1..2..2..3..4
..2..3..4..5..5....2..2..3..4..5....2..3..3..4..5....1..2..3..4..5
		

Crossrefs

Column 5 of A252820.

Formula

Empirical: a(n) = (1/259200)*n^10 + (1/6480)*n^9 + (149/60480)*n^8 + (163/7560)*n^7 + (10411/86400)*n^6 + (209/432)*n^5 + (17977/12960)*n^4 + (6043/3240)*n^3 + (37673/12600)*n^2 + (1423/1260)*n + 3.
Conjectures from Colin Barker, Dec 06 2018: (Start)
G.f.: x*(11 - 40*x + 182*x^2 - 430*x^3 + 711*x^4 - 822*x^5 + 657*x^6 - 360*x^7 + 131*x^8 - 29*x^9 + 3*x^10) / (1 - x)^11.
a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11) for n>11.
(End)

A252818 Number of n X 6 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

16, 147, 1032, 5490, 23664, 86724, 279300, 809349, 2147638, 5289321, 12219498, 26705926, 55598468, 110890224, 212893984, 395014703, 710759820, 1243830839, 2122388828, 3538891338, 5777267504, 9249641452, 14545342212, 22495562705
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Comments

Column 6 of A252820.

Examples

			Some solutions for n=4
..0..1..2..3..4..5....0..1..2..3..4..5....0..1..2..3..3..4....0..1..2..2..3..4
..1..2..2..3..4..5....1..2..3..4..4..5....1..2..3..4..4..5....1..2..2..2..3..4
..2..3..3..3..4..5....2..2..3..4..5..5....1..2..3..4..5..5....2..3..3..3..4..5
..3..3..3..4..5..6....3..3..4..5..5..6....1..2..3..4..5..6....3..4..4..4..5..6
		

Crossrefs

Cf. A252820.

Formula

Empirical: a(n) = (1/11404800)*n^12 + (1/211200)*n^11 + (37/345600)*n^10 + (143/103680)*n^9 + (27977/2419200)*n^8 + (83399/1209600)*n^7 + (319693/1036800)*n^6 + (34283/34560)*n^5 + (59941/28800)*n^4 + (482543/129600)*n^3 + (720359/277200)*n^2 + (44551/13860)*n + 3.

A252819 Number of nX7 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Original entry on oeis.org

22, 246, 2067, 13015, 65711, 279300, 1033761, 3414257, 10248688, 28359679, 73160199, 177550620, 408377425, 895696589, 1883020893, 3810974274, 7452779978, 14128342036, 26035049083, 46748705613, 81968236755, 140604294490
Offset: 1

Views

Author

R. H. Hardin, Dec 22 2014

Keywords

Comments

Column 7 of A252820

Examples

			Some solutions for n=4
..0..1..1..2..3..4..5....0..1..2..3..4..5..5....0..1..2..3..3..4..4
..0..1..2..3..3..4..5....1..2..3..3..4..5..5....1..2..3..3..4..4..5
..1..2..3..3..4..5..6....2..3..3..4..5..6..6....1..2..3..4..5..5..6
..2..3..4..4..5..6..7....3..4..4..5..6..7..7....1..2..3..4..5..6..7
		

Formula

Empirical: a(n) = (1/660441600)*n^14 + (1/9434880)*n^13 + (1/311850)*n^12 + (283/4989600)*n^11 + (23/34560)*n^10 + (5/896)*n^9 + (55843/1587600)*n^8 + (153973/907200)*n^7 + (4462807/7257600)*n^6 + (239717/145152)*n^5 + (50459/14400)*n^4 + (1240207/302400)*n^3 + (269664683/50450400)*n^2 + (308941/120120)*n + 4
Showing 1-7 of 7 results.