A228280 - OEIS

A228280

Number of nX5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or nw-se diagonally.

5, 13, 112, 587, 3631, 21166, 126119, 745178, 4416695, 26150120, 154877307, 917205757, 5431915952, 32169045631, 190512481196, 1128258633821, 6681806858103, 39571194265886, 234349700556332, 1387872742075595

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OFFSET

1,1

COMMENTS

Column 5 of A228285.

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (1, 21, 48, 14, -69, -38, 68, 13, -57, 37, -8, -2, 1).

FORMULA

a(n) = a(n-1) +21*a(n-2) +48*a(n-3) +14*a(n-4) -69*a(n-5) -38*a(n-6) +68*a(n-7) +13*a(n-8) -57*a(n-9) +37*a(n-10) -8*a(n-11) -2*a(n-12) +a(n-13)

G.f.: x*(5 + 8*x - 6*x^2 - 38*x^3 - 2*x^4 - 5*x^5 + 45*x^6 - 51*x^7 + 26*x^8 - 4*x^9 - 2*x^10 + x^11)/((1 + 2*x - 2*x^3 + x^4)*(1 - 3*x - 15*x^2 - 16*x^3 + 11*x^4 + 20*x^5 - 19*x^6 + 8*x^7 - x^9)). - M. F. Hasler, Apr 27 2014

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

See A228277-A228285, especially the latter.

See also the k=5 variants of A228390, A228476, A228506 etc.

Sequence in context: A106046 A180362 A117527 * A155175 A155185 A213129

Adjacent sequences: A228277 A228278 A228279 * A228281 A228282 A228283

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 19 2013

EXTENSIONS

Edited by N. J. A. Sloane, Aug 22 2013

STATUS

approved