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A250967
Number of (n+1) X (2+1) 0..1 arrays with no 2 X 2 subblock having the sum of its diagonal elements less than the absolute difference of its antidiagonal elements.
1
49, 308, 1945, 12281, 77537, 489543, 3090834, 19514643, 123209858, 777911692, 4911511266, 31009873218, 195787443967, 1236145757310, 7804669708967, 49276445682891, 311117342524943, 1964305653103961, 12402062409962968
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) - 13*a(n-2) + 17*a(n-3) - 14*a(n-4) + 3*a(n-5).
Empirical g.f.: x*(49 - 84*x + 118*x^2 - 108*x^3 + 24*x^4) / ((1 - x)*(1 - 7*x + 6*x^2 - 11*x^3 + 3*x^4)). - Colin Barker, Nov 24 2018
EXAMPLE
Some solutions for n=4:
1 1 0 0 1 0 1 0 1 1 1 0 1 0 1 1 1 1 1 1 1
1 0 1 1 0 0 1 1 1 1 1 1 1 0 1 0 0 1 0 0 0
0 1 1 0 1 1 1 0 1 1 1 1 0 1 1 0 1 0 1 1 1
0 1 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 1 1 1
1 0 1 1 0 0 1 0 1 1 1 0 0 1 0 1 1 0 0 0 0
CROSSREFS
Column 2 of A250973.
Sequence in context: A239607 A227079 A251222 * A245033 A340124 A017474
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 29 2014
STATUS
approved