A251321 Number of (n+1)X(3+1) 0..1 arrays with every 2X2 subblock having one or two 1s

78, 474, 2804, 17216, 104058, 636404, 3866110, 23591052, 143559096, 875140808, 5328991184, 32472642112, 197786681730, 1205033401542, 7340463039856, 44719514573220, 272420315443266, 1659593368284708, 10110004461011850

Offset

1,1

Comments

Column 3 of A251326

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +24*a(n-2) -59*a(n-3) -90*a(n-4) +188*a(n-5) +51*a(n-6) -126*a(n-7) +16*a(n-8) +11*a(n-9) -2*a(n-10)

Example

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

Crossrefs

Sequence in context: A231461 A007255 A003913 * A074089 A117329 A057798

Adjacent sequences: A251318 A251319 A251320 * A251322 A251323 A251324

Keyword

nonn

Author

R. H. Hardin, Dec 01 2014

Status

approved