A181248 - OEIS

A181248

Number of nX5 binary matrices with no 2X2 block having four 1's

32, 819, 22077, 587920, 15701273, 419045269, 11185495872, 298561305103, 7969215344753, 212714316418464, 5677773794982333, 151551208150533689, 4045206823611571168, 107974712600136074779, 2882062422625926933109

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OFFSET

1,1

COMMENTS

Column 5 of A181253

LINKS

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

FORMULA

Empirical: a(n)=20*a(n-1)+188*a(n-2)-192*a(n-3)-1660*a(n-4)+2804*a(n-5)-507*a(n-6)-624*a(n-7)

CROSSREFS

Sequence in context: A282396 A297099 A238771 * A139677 A231161 A220460

Adjacent sequences: A181245 A181246 A181247 * A181249 A181250 A181251

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 10 2010

STATUS

approved