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A258893 Number of (n+2) X (7+2) 0..1 arrays with no 3 X 3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum. 1
271350, 104329, 33252, 17424, 21320, 26244, 32400, 40000, 49288, 60516, 74000, 90000, 108936, 131044, 156880, 186624, 221000, 260100, 304848, 355216, 412360, 476100, 547856, 627264, 716040, 813604, 922000, 1040400, 1171208, 1313316 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n > 11.

Empirical for n mod 2 = 0: a(n) = n^4 + 10*n^3 + 217*n^2 + 960*n + 9216 for n > 3.

Empirical for n mod 2 = 1: a(n) = n^4 + 10*n^3 + 218*n^2 + 946*n + 9265 for n > 3.

Empirical g.f.: x*(271350 - 438371*x - 718106*x^2 + 1370362*x^3 + 545942*x^4 - 1479832*x^5 - 41458*x^6 + 602478*x^7 - 38780*x^8 - 54557*x^9 - 18836*x^10) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Dec 23 2018

EXAMPLE

Some solutions for n=1:

  0 0 1 0 0 1 0 0 0      1 0 0 0 0 0 1 0 0

  1 1 1 1 1 1 1 1 0      1 0 1 1 1 1 0 1 0

  0 0 1 0 1 1 1 0 1      0 0 0 0 0 0 1 0 1

CROSSREFS

Column 7 of A258894.

Sequence in context: A206001 A244561 A137715 * A237181 A013998 A236623

Adjacent sequences:  A258890 A258891 A258892 * A258894 A258895 A258896

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 14 2015

STATUS

approved

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Last modified January 22 15:57 EST 2019. Contains 319364 sequences. (Running on oeis4.)