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

A224403 Number of n X n 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

2, 12, 100, 884, 7812, 68282, 590254, 5055858, 42996954, 363652198, 3062704166, 25711681080, 215327121414, 1799987423914, 15026012170736, 125307656075926, 1044220994847456, 8697261784264396, 72413790737672880, 602789200212580366
Offset: 1

Views

Author

R. H. Hardin Apr 05 2013

Keywords

Comments

Diagonal of A224409

Examples

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

A224404 Number of n X 3 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

7, 28, 100, 358, 1288, 4636, 16684, 60040, 216064, 777544, 2798128, 10069552, 36237040, 130405312, 469286272, 1688808544, 6077472256, 21870844480, 78706050496, 283237457536, 1019279418112, 3668054858368, 13200135512320
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Column 3 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) + 2*a(n-3).
Empirical g.f.: x*(7 + 2*x^2) / (1 - 4*x + 2*x^2 - 2*x^3). - Colin Barker, Aug 30 2018

A224405 Number of n X 4 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

11, 56, 228, 884, 3436, 13440, 52700, 206708, 810664, 3178940, 12465596, 48881440, 191679756, 751638532, 2947419144, 11557788332, 45321842028, 177721660896, 696904347580, 2732788270804, 10716150306024, 42021505514844
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Column 4 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = 5*a(n-1) - 5*a(n-2) + 2*a(n-3) + 4*a(n-4).
Empirical g.f.: x*(11 + x + 3*x^2 + 2*x^3) / (1 - 5*x + 5*x^2 - 2*x^3 - 4*x^4). - Colin Barker, Aug 30 2018

A224406 Number of n X 5 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

16, 101, 465, 1928, 7812, 31710, 129402, 529846, 2172346, 8908986, 36534670, 149811438, 614276002, 2518688490, 10327233902, 42344211246, 173621959826, 711894378346, 2918949452350, 11968441441998, 49073678703842
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Column 5 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = 6*a(n-1) - 9*a(n-2) + 4*a(n-3) + 2*a(n-4) + 8*a(n-5).
Empirical g.f.: x*(1 - x)*(16 + 21*x + 24*x^2 + 7*x^3) / (1 - 6*x + 9*x^2 - 4*x^3 - 2*x^4 - 8*x^5). - Colin Barker, Aug 30 2018

A224407 Number of n X 6 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

22, 169, 879, 3902, 16420, 68282, 284254, 1187830, 4979464, 20913026, 87905004, 369597368, 1554028138, 6533901986, 27470619810, 115492192540, 485546657850, 2041301158120, 8581884687952, 36079321433650, 151682073514422
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Column 6 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = 7*a(n-1) -14*a(n-2) +9*a(n-3) +4*a(n-5) +16*a(n-6) for n>7.
Empirical g.f.: x*(22 + 15*x + 4*x^2 - 83*x^3 - 109*x^4 - 29*x^5 + 14*x^6) / (1 - 7*x + 14*x^2 - 9*x^3 - 4*x^5 - 16*x^6). - Colin Barker, Aug 30 2018

A224408 Number of n X 7 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

29, 267, 1568, 7490, 32814, 139638, 590254, 2496332, 10583872, 44986080, 191565628, 816675452, 3483688120, 14864259432, 63428734440, 270666075032, 1154981259240, 4928419635424, 21029737949696, 89733758819456
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Column 7 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = 8*a(n-1) - 20*a(n-2) + 18*a(n-3) - 4*a(n-4) + 2*a(n-5) + 8*a(n-6) + 32*a(n-7) for n>8.
Empirical g.f.: x*(29 + 35*x + 12*x^2 - 236*x^3 - 436*x^4 - 288*x^5 + 116*x^6 + 168*x^7) / (1 - 8*x + 20*x^2 - 18*x^3 + 4*x^4 - 2*x^5 - 8*x^6 - 32*x^7). - Colin Barker, Aug 30 2018

A224410 Number of 3 X n 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

8, 36, 100, 228, 465, 879, 1568, 2668, 4362, 6890, 10560, 15760, 22971, 32781, 45900, 63176, 85612, 114384, 150860, 196620, 253477, 323499, 409032, 512724, 637550, 786838, 964296, 1174040, 1420623, 1709065, 2044884, 2434128, 2883408, 3399932
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Row 3 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = (1/720)*n^6 + (1/48)*n^5 + (29/144)*n^4 + (13/16)*n^3 + (2087/360)*n^2 + (7/6)*n.
Conjectures from Colin Barker, Aug 30 2018: (Start)
G.f.: x*(8 - 20*x + 16*x^2 + 4*x^3 - 11*x^4 + 4*x^5) / (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)

A224411 Number of 4 X n 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

16, 108, 358, 884, 1928, 3902, 7490, 13784, 24467, 42053, 70195, 114073, 180875, 280385, 425693, 634043, 927836, 1335806, 1894388, 2649298, 3657346, 4988504, 6728252, 8980226, 11869193, 15544379, 20183177, 25995263, 33227149, 42167203
Offset: 1

Views

Author

R. H. Hardin, Apr 05 2013

Keywords

Comments

Row 4 of A224409.

Examples

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

Crossrefs

Cf. A224409.

Formula

Empirical: a(n) = (1/40320)*n^8 + (1/1440)*n^7 + (31/2880)*n^6 + (13/144)*n^5 + (3767/5760)*n^4 + (6409/1440)*n^3 + (189859/10080)*n^2 - (73/24)*n - 7 for n>2.
Conjectures from Colin Barker, Aug 30 2018: (Start)
G.f.: x*(16 - 36*x - 38*x^2 + 206*x^3 - 196*x^4 - 106*x^5 + 368*x^6 - 334*x^7 + 155*x^8 - 38*x^9 + 4*x^10) / (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>11.
(End)

A224412 Number of 5Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

32, 324, 1288, 3436, 7812, 16420, 32814, 63202, 118117, 214919, 381436, 661132, 1120283, 1857749, 3018052, 4808608, 7522116, 11565280, 17495232, 26065236, 38281486, 55473066, 79377418, 112243966, 156958871, 217194245, 297585532
Offset: 1

Views

Author

R. H. Hardin Apr 05 2013

Keywords

Comments

Row 5 of A224409

Examples

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

Formula

Empirical: a(n) = (1/3628800)*n^10 + (1/80640)*n^9 + (1/3456)*n^8 + (23/5760)*n^7 + (7213/172800)*n^6 + (683/2304)*n^5 + (138869/36288)*n^4 + (32143/2240)*n^3 + (32909/450)*n^2 - (753/20)*n - 44 for n>3

A224413 Number of 6Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

Original entry on oeis.org

64, 972, 4636, 13440, 31710, 68282, 139638, 275766, 530583, 999049, 1844709, 3342831, 5946316, 10384152, 17805490, 29986574, 49622914, 80735424, 129226948, 203634878, 316136662, 483878162, 730710330, 1089437826, 1604704333
Offset: 1

Views

Author

R. H. Hardin Apr 05 2013

Keywords

Comments

Row 6 of A224409

Examples

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

Formula

Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (199/43545600)*n^10 + (1/10752)*n^9 + (19951/14515200)*n^8 + (5143/345600)*n^7 + (6148357/43545600)*n^6 + (3015961/1451520)*n^5 + (128983289/10886400)*n^4 + (40193333/604800)*n^3 + (444089893/1663200)*n^2 - (4351/20)*n - 222 for n>4
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