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A186121 Number of (n+1) X 3 binary arrays with every 2 X 2 subblock diagonal sum less antidiagonal sum equal to some horizontal or vertical neighbor 2 X 2 subblock diagonal sum less antidiagonal sum. 1
14, 38, 94, 254, 682, 1878, 5214, 14606, 41138, 116350, 330046, 938174, 2670826, 7611430, 21707790, 61943694, 176825074, 504902766, 1441965358, 4118707422, 11765461418, 33611411190, 96025298558, 274346613774, 783834214130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A186128.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 5*a(n-1) - 3*a(n-2) - 13*a(n-3) + 6*a(n-4) + 14*a(n-5) + 6*a(n-6) + 8*a(n-7) - 16*a(n-8) - 16*a(n-9).

Empirical g.f.: 2*x*(7 - 16*x - 27*x^2 + 40*x^3 + 52*x^4 + 14*x^5 - 4*x^6 - 72*x^7 - 64*x^8) / ((1 - 2*x)*(1 - 3*x - 3*x^2 + 7*x^3 + 8*x^4 + 2*x^5 - 2*x^6 - 12*x^7 - 8*x^8)). - Colin Barker, Apr 17 2018

EXAMPLE

Some solutions for 5 X 3:

..0..1..1....0..0..1....1..0..0....0..0..1....0..0..1....0..1..1....0..0..1

..1..1..1....0..0..1....1..1..1....1..1..1....1..0..0....1..1..0....1..1..1

..1..0..0....1..0..0....0..1..1....1..1..0....0..0..1....1..1..1....1..1..0

..0..0..1....0..0..0....0..0..0....1..1..1....0..0..1....0..0..1....1..1..0

..0..0..1....0..1..1....1..0..0....0..0..1....0..0..1....0..0..1....0..1..1

CROSSREFS

Cf. A186128.

Sequence in context: A256560 A058826 A142241 * A231391 A231459 A244702

Adjacent sequences:  A186118 A186119 A186120 * A186122 A186123 A186124

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 13 2011

STATUS

approved

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Last modified January 24 09:43 EST 2022. Contains 350534 sequences. (Running on oeis4.)