A224688 Number of (n+4) X 10 0..1 matrices with each 5 X 5 subblock idempotent.

5385, 2110, 2354, 2646, 2926, 3158, 3819, 4858, 6192, 7747, 9470, 11789, 15081, 19640, 25686, 33386, 43335, 56505, 74162, 97792, 129048, 170178, 224402, 296206, 391562, 518095, 685678, 907404, 1200852, 1589573, 2104743, 2787411, 3691719

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-5) - 3*a(n-6) + 3*a(n-7) - a(n-8) for n>12.

Empirical g.f.: x*(5385 - 19430*x + 26224*x^2 - 15650*x^3 + 3411*x^4 - 5361*x^5 + 14558*x^6 - 12707*x^7 + 3439*x^8 + 69*x^9 + 57*x^10 + 4*x^11) / ((1 - x)^3*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 03 2018

Example

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

Crossrefs

Column 6 of A224690.

Sequence in context: A063408 A057850 A058325 * A335936 A335939 A328562

Adjacent sequences: A224685 A224686 A224687 * A224689 A224690 A224691

Keyword

nonn

Author

R. H. Hardin, Apr 15 2013

Status

approved