A251321 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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