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.

A278772 Number of n X 2 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

0, 2, 20, 117, 503, 1750, 5209, 13751, 33000, 73282, 152581, 300872, 566293, 1023724, 1786462, 3021818, 4971616, 7978746, 12521114, 19254543, 29066411, 43142066, 63046335, 90822745, 129113400, 181302810, 251689347, 345688410, 470071817
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Examples

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

Crossrefs

Column 2 of A278778.

Formula

Empirical: a(n) = (1/3628800)*n^10 + (1/80640)*n^9 + (1/3780)*n^8 + (17/8064)*n^7 + (1513/172800)*n^6 + (167/11520)*n^5 + (12329/362880)*n^4 + (197/4032)*n^3 - (2167/50400)*n^2 - (11/168)*n.
Conjectures from Colin Barker, Feb 10 2019: (Start)
G.f.: x^2*(2 - 2*x + 7*x^2 - 14*x^3 + 12*x^4 - 5*x^5 + x^6) / (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)

A278773 Number of nX3 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

0, 20, 266, 1972, 10784, 48501, 189595, 665212, 2138149, 6384894, 17895624, 47447755, 119746565, 289136007, 670787381, 1500673676, 3247602855, 6817025467, 13912884597, 27665820296, 53701416899, 101922145950, 189427147850
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Column 3 of A278778.

Examples

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

Crossrefs

Cf. A278778.

Formula

Empirical: a(n) = (1/121645100408832000)*n^19 + (1/800296713216000)*n^18 + (193/2134124568576000)*n^17 + (1/241416806400)*n^16 + (173/1280987136000)*n^15 + (26111/7846046208000)*n^14 + (12107647/188305108992000)*n^13 + (354047/362125209600)*n^12 + (113721193/9656672256000)*n^11 + (12542321/109734912000)*n^10 + (1257109487/1379524608000)*n^9 + (1427797621/241416806400)*n^8 + (1397907414289/47076277248000)*n^7 + (598789045909/5884534656000)*n^6 + (543697174847/2615348736000)*n^5 + (191422487/1005903360)*n^4 - (3436687523/44108064000)*n^3 - (46017833/154378224)*n^2 - (3115337/19399380)*n

A278774 Number of nX4 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

1, 117, 1972, 19750, 150085, 955347, 5355983, 27218249, 127644118, 559023840, 2305566900, 9009824325, 33520023813, 119176965881, 406212717567, 1330964850429, 4202125841615, 12811256626245, 37790376053439
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Column 4 of A278778.

Examples

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

Crossrefs

Cf. A278778.

Formula

Empirical polynomial of degree 36 (see link above)

A278775 Number of nX5 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

6, 503, 10784, 150085, 1673658, 16205001, 141166787, 1126917480, 8340736743, 57745890265, 376707516550, 2329550843590, 13722943412752, 77304542920321, 417679484040714, 2169521229525151, 10853156575543255, 52367994237483811
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Column 5 of A278778.

Examples

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

Crossrefs

Cf. A278778.

Formula

Empirical polynomial of degree 69 (see link above)

A278776 Number of nX6 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

21, 1750, 48501, 955347, 16205001, 251740932, 3634987413, 48847405083, 611199661843, 7140933364136, 78280456105686, 809842005695656, 7953581118077240, 74557744904209329, 670158115881138987
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Column 6 of A278778.

Examples

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

Crossrefs

Cf. A278778.

Formula

Empirical polynomial of degree 134 (see link above)

A278777 Number of nX7 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

56, 5209, 189595, 5355983, 141166787, 3634987413, 90752836672, 2155380363189, 48042054699217, 999491681597761, 19416161058987737, 353517442918850559, 6065787121333416262, 98680235108923294584, 1531317900358396738494
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Column 7 of A278778.

Examples

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

Crossrefs

Cf. A278778.

A278771 Number of n X n 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

Original entry on oeis.org

0, 2, 266, 19750, 1673658, 251740932, 90752836672, 93037538287080, 293564184229043556, 2953569640505846392444
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2016

Keywords

Comments

Diagonal of A278778.

Examples

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

Crossrefs

Cf. A278778.
Showing 1-7 of 7 results.