A224686 Number of (n+4) X 8 0..1 matrices with each 5 X 5 subblock idempotent.

3465, 1720, 1896, 2166, 2429, 2646, 3214, 4122, 5307, 6699, 8253, 10313, 13224, 17256, 22621, 29474, 38326, 50021, 65685, 86644, 114391, 150918, 199073, 262818, 347453, 459759, 608521, 805360, 1065871, 1410937, 1868234, 2474211, 3276950

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - 2*a(n-6) + 2*a(n-8) - a(n-9) for n>13.

Empirical g.f.: x*(3465 - 8675*x + 3666*x^2 + 6848*x^3 - 7232*x^4 - 1677*x^5 + 5708*x^6 + 1572*x^7 - 5764*x^8 + 1869*x^9 + 158*x^10 + 56*x^11 + 4*x^12) / ((1 - x)^3*(1 + x)*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 03 2018

Example

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

Crossrefs

Column 4 of A224690.

Sequence in context: A235586 A252967 A252959 * A125017 A307111 A307098

Adjacent sequences: A224683 A224684 A224685 * A224687 A224688 A224689

Keyword

nonn

Author

R. H. Hardin, Apr 15 2013

Status

approved