A224620 Number of (n+4)X7 0..2 matrices with each 5X5 subblock idempotent

23914, 19596, 24024, 26624, 28058, 28949, 36576, 48835, 63548, 79494, 96070, 120095, 156156, 206698, 272947, 355586, 462001, 604267, 796828, 1055426, 1396436, 1843643, 2432843, 3214414, 4254348, 5635048, 7462704, 9879362, 13077330

Offset

1,1

Comments

Column 3 of A224625

Links

R. H. Hardin, Table of n, a(n) for n = 1..96

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -a(n-4) -a(n-7) +a(n-8) -a(n-9) +a(n-10) +a(n-12) -a(n-13) for n>17

Example

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

Crossrefs

Sequence in context: A251904 A239177 A204359 * A263156 A263153 A233882

Adjacent sequences: A224617 A224618 A224619 * A224621 A224622 A224623

Keyword

nonn

Author

R. H. Hardin Apr 12 2013

Status

approved