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.

A188824 T(n,k) = number of n X k binary arrays without the pattern 0 1 diagonally or antidiagonally.

Original entry on oeis.org

2, 4, 4, 8, 9, 8, 16, 25, 16, 16, 32, 64, 48, 25, 32, 64, 169, 144, 81, 36, 64, 128, 441, 432, 256, 120, 49, 128, 256, 1156, 1296, 841, 400, 169, 64, 256, 512, 3025, 3888, 2704, 1360, 576, 224, 81, 512, 1024, 7921, 11664, 8836, 4624, 2025, 784, 289, 100, 1024, 2048
Offset: 1

Views

Author

R. H. Hardin, Apr 11 2011

Keywords

Comments

Table starts
....2...4...8...16...32....64...128....256.....512....1024.....2048.....4096
....4...9..25...64..169...441..1156...3025....7921...20736....54289...142129
....8..16..48..144..432..1296..3888..11664...34992..104976...314928...944784
...16..25..81..256..841..2704..8836..28561...93025..301401...980100..3179089
...32..36.120..400.1360..4624.15776..53824..183744..627264..2141568..7311616
...64..49.169..576.2025..7056.24964..87616..310249.1092025..3865156.13623481
..128..64.224..784.2800.10000.36000.129600..468000.1690000..6110000.22090000
..256..81.289.1024.3721.13456.49284.179776..660969.2421136..8916196.32729841
..512.100.360.1296.4752.17424.64416.238144..884256.3283344.12220128.45481536
.1024.121.441.1600.5929.21904.81796.304704.1142761.4276624.16080100.60341824

Examples

			Some solutions for 5X3
..1..1..1....1..1..1....1..1..1....1..1..1....1..1..1....0..1..0....1..1..1
..1..1..1....0..1..1....1..0..1....1..1..1....1..1..1....1..0..1....1..1..1
..1..1..1....0..0..1....0..1..0....1..1..1....0..1..0....0..1..0....0..1..1
..1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....1..0..1....1..0..1
..1..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..0
		

Crossrefs

Column 2 is A000290(n+1).
Column 4 is A016802.
Row 2 is A007598(n+2).

Formula

Empirical: a(n,1) = 2^n
Empirical: a(n,2) = n^2 + 2*n + 1
Empirical: a(n,3) = 2*a(n-1,3) - 2*a(n-3,3) + a(n-4,3)
Empirical: a(n,4) = 16*n^2
Empirical: a(n,5) = 2*a(n-1,5) - 2*a(n-3,5) + a(n-4,5) for n>5
Empirical: a(n,6) = 256*n^2 - 384*n + 144 for n>2
Empirical: a(n,7) = 2*a(n-1,7) - 2*a(n-3,7) + a(n-4,7) for n>7
Empirical: a(n,8) = 4096*n^2 - 11264*n + 7744 for n>4