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A070051
Number of Bottleneck-Monge matrices with 3 rows. In the formula below, P=3.
8
8, 33, 117, 384, 1194, 3558, 10238, 28606, 77950, 207870, 543998, 1400318, 3552254, 8894462, 22011902, 53903358, 130744318, 314376190, 749928446, 1775894526, 4177264638, 9764863998, 22695378942, 52466548734, 120686903294, 276320747518, 629900574718
OFFSET
1,1
COMMENTS
Bottleneck-Monge matrices are {0,1} matrices A in which, for every i<j and k<l, max(A[i,l],A[j,k]) <= max(A[i,k],A[j,l]).
LINKS
FORMULA
a(N) = a(3, N), where a(P, N) is defined recursively in A070050.
Empirical G.f.: -x*(32*x^5-140*x^4+213*x^3-154*x^2+55*x-8) / ((x-1)*(2*x-1)^5). - Colin Barker, Feb 28 2013
KEYWORD
nonn,easy
AUTHOR
Pascal Prea (pascal.prea(AT)lim.univ-mrs.fr), Apr 18 2002
EXTENSIONS
a(10) - a(27) from Nathaniel Johnston, Apr 13 2011
STATUS
approved