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.

A278319 Number of n X 2 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

0, 3, 20, 94, 395, 1492, 4991, 14848, 39832, 97835, 223015, 477126, 966849, 1869504, 3470210, 6214384, 10780448, 18178763, 29884150, 48010910, 75541039, 116618372, 176923705, 264148560, 388588200, 563877795, 807899313, 1143890790, 1601794149
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Examples

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

Crossrefs

Column 2 of A278325.

Formula

Empirical: a(n) = (1/39916800)*n^11 + (1/725760)*n^10 + (13/362880)*n^9 + (43/120960)*n^8 + (223/172800)*n^7 - (227/34560)*n^6 + (1019/45360)*n^5 + (27263/181440)*n^4 + (12193/113400)*n^3 - (121/840)*n^2 - (13/99)*n.
Conjectures from Colin Barker, Feb 09 2019: (Start)
G.f.: x^2*(3 - 16*x + 52*x^2 - 73*x^3 + 41*x^4 + x^5 - 10*x^6 + 3*x^7) / (1 - x)^12.
a(n) = 12*a(n-1) - 66*a(n-2) + 220*a(n-3) - 495*a(n-4) + 792*a(n-5) - 924*a(n-6) + 792*a(n-7) - 495*a(n-8) + 220*a(n-9) - 66*a(n-10) + 12*a(n-11) - a(n-12) for n>12.
(End)

A278320 Number of nX3 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

0, 20, 236, 1678, 9714, 51229, 251892, 1144205, 4762445, 18164685, 63838081, 208288721, 635843575, 1829104046, 4989647446, 12978273537, 32338548895, 77506161543, 179299342255, 401569610694, 873025241923, 1846627291485
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Column 3 of A278325.

Examples

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

Crossrefs

Cf. A278325.

Formula

Empirical: a(n) = (1/25852016738884976640000)*n^23 + (1/102181884343418880000)*n^22 + (1/858671297003520000)*n^21 + (1259/14597412049059840000)*n^20 + (3617/810967336058880000)*n^19 + (1831/10670622842880000)*n^18 + (13746263/2688996956405760000)*n^17 + (19040863/158176291553280000)*n^16 + (101471197/45193226158080000)*n^15 + (1480973341/45193226158080000)*n^14 + (61001884543/165708495912960000)*n^13 + (3617038307/1158800670720000)*n^12 + (1537519018181/79088145776640000)*n^11 + (13469195909881/158176291553280000)*n^10 + (4270693429711/11298306539520000)*n^9 + (9457223412823/2824576634880000)*n^8 + (218151538495819/8002967132160000)*n^7 + (775352818331437/8002967132160000)*n^6 + (627425471079349/3478413818880000)*n^5 + (3995289195644399/14783258730240000)*n^4 + (6585215991983/43020065088000)*n^3 - (217394476291/586637251200)*n^2 - (1933447697/5354228880)*n

A278321 Number of nX4 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

1, 94, 1678, 19854, 186987, 1548002, 11947350, 87562135, 605431820, 3905165468, 23355599964, 129475795828, 667503759881, 3215875683718, 14555156486463, 62204964640341, 252211338710097, 974245904884957, 3598868691539578
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Column 4 of A278325.

Examples

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

Crossrefs

Cf. A278325.

Formula

Empirical polynomial of degree 47 (see link above)

A278322 Number of nX5 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

6, 395, 9714, 186987, 3058990, 43798840, 570738085, 7010453565, 82490704797, 927749763030, 9874571566773, 98622311006346, 920542037366117, 8028589976371346, 65570255252201804, 503146509213296224
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Column 5 of A278325.

Examples

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

Crossrefs

Cf. A278325.

Formula

Empirical polynomial of degree 95 (see link above)

A278323 Number of nX6 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

21, 1492, 51229, 1548002, 43798840, 1133034160, 26606146271, 577253086055, 11856994168275, 234252250004719, 4462457602929707, 81437338008292870, 1411665474225016752, 23098384621606953307, 355699829714059120732
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Column 6 of A278325.

Examples

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

Crossrefs

Cf. A278325.

A278324 Number of nX7 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

56, 4991, 251892, 11947350, 570738085, 26606146271, 1159826452573, 46588303100299, 1741053359883624, 61687083048618477, 2105403821298913363, 69685735738121699248, 2231675758500253736280, 68674888544867993485304
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Column 7 of A278325.

Examples

			Some solutions for n=2
..1..0..1..1..0..0..0. .0..0..1..1..1..0..0. .0..0..1..1..1..1..0
..1..1..0..1..1..1..1. .0..0..0..0..1..0..0. .1..1..1..0..0..0..0
		

Crossrefs

Cf. A278325.

A278318 Number of n X n 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

Original entry on oeis.org

0, 3, 236, 19854, 3058990, 1133034160, 1159826452573, 3539023342110534, 33693644340398789900, 1032075934040317150939325
Offset: 1

Views

Author

R. H. Hardin, Nov 18 2016

Keywords

Comments

Diagonal of A278325.

Examples

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

Crossrefs

Cf. A278325.
Showing 1-7 of 7 results.