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.
49, 308, 1945, 12281, 77537, 489543, 3090834, 19514643, 123209858, 777911692, 4911511266, 31009873218, 195787443967, 1236145757310, 7804669708967, 49276445682891, 311117342524943, 1964305653103961, 12402062409962968
Offset: 1
Keywords
Examples
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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Column 2 of A250973.
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