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 14 results. Next

A250791 Number of (n+1) X (2+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

24, 66, 180, 490, 1336, 3646, 9956, 27194, 74288, 202950, 554460, 1514802, 4138504, 11306590, 30890164, 84393482, 230567264, 629921462, 1720977420, 4701797730, 12845550264, 35094695950, 95880492388, 261950376634, 715661738000
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Column 2 of A250797.

Formula

Empirical: a(n) = 4*a(n-1) - 3*a(n-2) - 2*a(n-3) + 2*a(n-4).
Conjectures from Colin Barker, Nov 20 2018: (Start)
G.f.: 2*x*(12 - 15*x - 6*x^2 + 8*x^3) / ((1 - x)^2*(1 - 2*x - 2*x^2)).
a(n) = (-6 + (39-23*sqrt(3))*(1-sqrt(3))^n + 39*(1+sqrt(3))^n + 23*sqrt(3)*(1+sqrt(3))^n + 6*n) / 9.
(End)

A250792 Number of (n+1) X (3+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

54, 162, 482, 1430, 4258, 12706, 37986, 113694, 340562, 1020650, 3059890, 9175558, 27518466, 82538994, 247584194, 742687022, 2227929970, 6683527738, 20050058898, 60149128086, 180445287074, 541331666882, 1623986612002, 4871943058750
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Column 3 of A250797.

Formula

Empirical: a(n) = 6*a(n-1) - 10*a(n-2) + 11*a(n-4) - 6*a(n-5).
Conjectures from Colin Barker, Nov 20 2018: (Start)
G.f.: 2*x*(27 - 81*x + 25*x^2 + 79*x^3 - 48*x^4) / ((1 - x)^2*(1 + x)*(1 - 2*x)*(1 - 3*x)).
a(n) = -3 - (-1)^n/4 + 2^(1+n) + (23*3^(1+n))/4 + n.
(End)

A250793 Number of (n+1) X (4+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

118, 376, 1190, 3776, 12062, 38676, 124366, 400616, 1292134, 4171276, 13474406, 43546448, 140781326, 455247108, 1472416318, 4762930232, 15408574198, 49852141564, 161298304598, 521908159904, 1688775756830, 5464620624372
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Column 4 of A250797.

Formula

Empirical: a(n) = 8*a(n-1) - 20*a(n-2) + 8*a(n-3) + 33*a(n-4) - 36*a(n-5) + 8*a(n-7).
Empirical g.f.: 2*x*(59 - 284*x + 271*x^2 + 416*x^3 - 624*x^4 + 10*x^5 + 128*x^6) / ((1 - x)^2*(1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x - 4*x^2)). - Colin Barker, Nov 20 2018

A250794 Number of (n+1) X (5+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

252, 838, 2776, 9258, 31220, 105954, 361344, 1236058, 4237556, 14549610, 50012080, 172050098, 592248148, 2039649282, 7026884288, 24215293674, 83465955764, 287740551770, 992085339216, 3420905014178, 11796889975188, 40683768017330
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Column 5 of A250797.

Formula

Empirical: a(n) = 10*a(n-1) - 33*a(n-2) + 24*a(n-3) + 79*a(n-4) - 138*a(n-5) - 3*a(n-6) + 100*a(n-7) - 18*a(n-8) - 20*a(n-9).
Empirical g.f.: 2*x*(126 - 841*x + 1356*x^2 + 1552*x^3 - 4886*x^4 + 609*x^5 + 3484*x^6 - 580*x^7 - 640*x^8) / ((1 - x)^2*(1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x - 2*x^2)*(1 - 2*x - 5*x^2)). - Colin Barker, Nov 20 2018

A250795 Number of (n+1) X (6+1) 0..1 arrays with nondecreasing min(x(i,j), x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

530, 1818, 6230, 21610, 76110, 270598, 968942, 3485538, 12580830, 45517150, 164970110, 598685226, 2174802030, 7906183238, 28758522030, 104655742642, 380990823486, 1387358367918, 5053131325982, 18408177907066, 67069331582158
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Comments

Column 6 of A250797.

Examples

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

Crossrefs

Cf. A250797.

Formula

Empirical: a(n) = 12*a(n-1) -49*a(n-2) +50*a(n-3) +165*a(n-4) -408*a(n-5) +a(n-6) +618*a(n-7) -224*a(n-8) -344*a(n-9) +108*a(n-10) +72*a(n-11).

A250796 Number of (n+1)X(7+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

1102, 3868, 13598, 48600, 177142, 653880, 2437366, 9144752, 34478398, 130446176, 494830430, 1880740552, 7158985446, 27281746344, 104059447110, 397187462784, 1516879760334, 5795614884304, 22151486206382, 84689884626136
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Comments

Column 7 of A250797

Examples

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

Formula

Empirical: a(n) = 14*a(n-1) -68*a(n-2) +88*a(n-3) +312*a(n-4) -1008*a(n-5) +62*a(n-6) +2576*a(n-7) -1535*a(n-8) -2790*a(n-9) +1886*a(n-10) +1456*a(n-11) -656*a(n-12) -336*a(n-13)

A250798 Number of (1+1) X (n+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

10, 24, 54, 118, 252, 530, 1102, 2272, 4654, 9486, 19260, 38986, 78726, 158672, 319318, 641830, 1288828, 2586018, 5185566, 10393024, 20821470, 41700254, 83493244, 167136538, 334515862, 669424560, 1339484742, 2679997942, 5361659964
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Row 1 of A250797.

Formula

Empirical: a(n) = 3*a(n-1) - a(n-2) - 2*a(n-3).
Empirical g.f.: 2*x*(5 - 3*x - 4*x^2) / ((1 - 2*x)*(1 - x - x^2)). - Colin Barker, Nov 20 2018

A250799 Number of (2+1) X (n+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

24, 66, 162, 376, 838, 1818, 3868, 8114, 16842, 34680, 70974, 144562, 293356, 593562, 1198210, 2414360, 4857750, 9762474, 19600956, 39324898, 78848794, 158019576, 316560142, 633963266, 1269290508, 2540787978, 5085146898, 10176071704
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Row 2 of A250797.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - a(n-3) + 2*a(n-4).
Empirical g.f.: 2*x*(12 - 15*x - 3*x^2 + 8*x^3) / ((1 - x)*(1 - 2*x)*(1 - x - x^2)). - Colin Barker, Nov 20 2018

A250800 Number of (3+1) X (n+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

58, 180, 482, 1190, 2776, 6230, 13598, 29084, 61274, 127630, 263544, 540558, 1102982, 2241420, 4540290, 9173622, 18497880, 37239590, 74873806, 150386236, 301805898, 605284030, 1213273912, 2430926110, 4868936566, 9749335980
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Row 3 of A250797.

Formula

Empirical: a(n) = 5*a(n-1) - 8*a(n-2) + 3*a(n-3) + 3*a(n-4) - 2*a(n-5).
Empirical g.f.: 2*x*(29 - 55*x + 23*x^2 + 23*x^3 - 16*x^4) / ((1 - x)^2*(1 - 2*x)*(1 - x - x^2)). - Colin Barker, Nov 20 2018

A250801 Number of (4+1) X (n+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

140, 490, 1430, 3776, 9258, 21610, 48600, 106426, 228342, 482496, 1007546, 2084962, 4284032, 8754018, 17810278, 36111264, 73018218, 147325946, 296740456, 596862762, 1199199990, 2407260800, 4828861690, 9680929586, 19399411088
Offset: 1

Views

Author

R. H. Hardin, Nov 27 2014

Keywords

Examples

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

Crossrefs

Row 4 of A250797.

Formula

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 9*a(n-3) + 9*a(n-4) + 6*a(n-5) - 8*a(n-6) -a(n-7) + 2*a(n-8).
Empirical g.f.: 2*x*(70 - 35*x - 125*x^2 + 148*x^3 + 82*x^4 - 125*x^5 - 15*x^6 + 32*x^7) / ((1 - x)^3*(1 + x)^2*(1 - 2*x)*(1 - x - x^2)). - Colin Barker, Nov 20 2018
Showing 1-10 of 14 results. Next