A266931 Number of n X 4 binary arrays with rows lexicographically nondecreasing and columns lexicographically nondecreasing and row sums nondecreasing and column sums nonincreasing.

2, 5, 12, 35, 100, 288, 794, 2077, 5110, 11869, 26086, 54543, 108999, 209148, 386883, 692473, 1203061, 2034487, 3357115, 5416951, 8563297, 13284702, 20254831, 30390893, 44926915, 65505045, 94288435, 134099783, 188589873, 262441858

Offset: 1

Author

R. H. Hardin, Jan 06 2016

Keywords

• nonn

Comments

Column 4 of A266935.

Examples

			Some solutions for n=4
..0..0..1..1....0..0..1..1....0..0..0..0....0..0..0..1....0..0..0..1
..1..1..0..1....1..1..0..0....0..0..0..1....0..0..1..0....1..1..1..0
..1..1..1..0....1..1..0..1....0..0..1..0....1..1..0..0....1..1..1..0
..1..1..1..1....1..1..1..0....1..1..0..0....1..1..0..0....1..1..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..64

Crossrefs

Cf. A266935.

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) -4*a(n-3) -9*a(n-4) -a(n-5) +19*a(n-6) +13*a(n-7) -13*a(n-8) -25*a(n-9) -11*a(n-10) +15*a(n-11) +22*a(n-12) +17*a(n-13) -4*a(n-14) -23*a(n-15) -23*a(n-16) -4*a(n-17) +17*a(n-18) +22*a(n-19) +15*a(n-20) -11*a(n-21) -25*a(n-22) -13*a(n-23) +13*a(n-24) +19*a(n-25) -a(n-26) -9*a(n-27) -4*a(n-28) +3*a(n-29) +2*a(n-30) -a(n-31).