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 1-5 of 5 results.

A227021 Number of n X 2 (0,1,2) arrays of permanents of 2 X 2 subblocks of some (n+1) X 3 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Original entry on oeis.org

7, 26, 72, 171, 368, 729, 1343, 2325, 3819, 6001, 9082, 13311, 18978, 26417, 36009, 48185, 63429, 82281, 105340, 133267, 166788, 206697, 253859, 309213, 373775, 448641, 534990, 634087, 747286, 876033, 1021869, 1186433, 1371465, 1578809
Offset: 1

Views

Author

R. H. Hardin, Jun 27 2013

Keywords

Examples

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

Crossrefs

Column 2 of A227025.

Formula

Empirical: a(n) = (1/40)*n^5 + (1/3)*n^4 - (1/8)*n^3 + (5/3)*n^2 + (141/10)*n - 15 for n>2.
Conjectures from Colin Barker, Sep 06 2018: (Start)
G.f.: x*(7 - 16*x + 21*x^2 - 11*x^3 + 7*x^4 - 6*x^5 + x^7) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A227022 Number of nX3 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Original entry on oeis.org

12, 72, 335, 1366, 4948, 16115, 47659, 129463, 326522, 771653, 1722005, 3652726, 7406710, 14426468, 27103102, 49288384, 87029344, 149600861, 250930856, 411535151, 661105246, 1041922558, 1613307461, 2457351181, 3686223670
Offset: 1

Views

Author

R. H. Hardin Jun 27 2013

Keywords

Comments

Column 3 of A227025

Examples

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

Formula

Empirical: a(n) = (1/2217600)*n^11 + (1/48384)*n^10 + (19/241920)*n^9 + (199/2800)*n^7 - (4291/11520)*n^6 - (3567/1792)*n^5 + (1336261/24192)*n^4 - (95295341/302400)*n^3 + (851237/1440)*n^2 + (8658337/9240)*n - 3550 for n>6

A227023 Number of nX4 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X5 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Original entry on oeis.org

18, 171, 1366, 10050, 65317, 375270, 1924848, 8908719, 37616613, 146387460, 529743352, 1796459014, 5746888515, 17440783714, 50456503591, 139731086307, 371756133099, 953183208702, 2361809765393, 5669196636680, 13211336518266
Offset: 1

Views

Author

R. H. Hardin Jun 27 2013

Keywords

Comments

Column 4 of A227025

Examples

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

A227024 Number of nX5 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X6 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Original entry on oeis.org

25, 368, 4948, 65317, 786154, 8379285, 79224749, 668706345, 5081503151, 35102679286, 222533536879, 1305789511714, 7145426639248, 36700964912428, 177929765359899, 818153315837912, 3583007628524884, 14999102522624015
Offset: 1

Views

Author

R. H. Hardin Jun 27 2013

Keywords

Comments

Column 5 of A227025

Examples

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

A227020 Number of n X n (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X(n+1) binary array with rows and columns of the latter in lexicographically nondecreasing order.

Original entry on oeis.org

3, 26, 335, 10050, 786154, 168973605, 104606988712
Offset: 1

Views

Author

R. H. Hardin Jun 27 2013

Keywords

Comments

Diagonal of A227025

Examples

			Some solutions for n=4
..0..0..1..1....0..1..0..1....0..0..1..1....0..0..0..1....0..1..0..1
..0..1..0..0....0..0..0..1....0..1..0..0....0..0..2..0....0..0..0..0
..1..0..0..1....0..1..1..1....1..0..1..1....0..1..0..1....1..1..0..1
..0..0..1..2....1..1..0..1....0..0..1..1....0..0..0..0....1..1..1..2
		
Showing 1-5 of 5 results.