A194616 Half the number of lower triangles of a 3X3 0..n array with no element equal to the average of its horizontal and vertical neighbors.

5, 96, 775, 3638, 12438, 34247, 82057, 175111, 344173, 630849, 1094898, 1812250, 2887675, 4445870, 6653357, 9703428, 13843860, 19356297, 26596343, 35955433, 47921851, 63027619, 81920692, 105300352, 134012453, 168951880, 211194991

Offset: 1

Author

R. H. Hardin Aug 30 2011

Keywords

• nonn

Comments

Row 2 of A194615

Examples

			Some solutions for n=2
..2......2......1......1......1......2......0......1......2......0......2
..0.2....1.0....0.2....0.2....2.2....0.2....2.0....0.2....0.2....1.0....1.1
..1.0.1..0.1.2..2.1.0..1.0.1..0.1.0..2.0.2..0.2.0..1.1.2..1.1.2..2.1.2..1.0.1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = -a(n-1) +a(n-3) +2*a(n-4) +3*a(n-5) +3*a(n-6) +a(n-7) -2*a(n-8) -5*a(n-9) -6*a(n-10) -6*a(n-11) -2*a(n-12) +2*a(n-13) +5*a(n-14) +7*a(n-15) +6*a(n-16) +2*a(n-17) -2*a(n-18) -4*a(n-19) -4*a(n-20) -a(n-21) +a(n-22) +4*a(n-23) +4*a(n-24) +2*a(n-25) -2*a(n-26) -6*a(n-27) -7*a(n-28) -5*a(n-29) -2*a(n-30) +2*a(n-31) +6*a(n-32) +6*a(n-33) +5*a(n-34) +2*a(n-35) -a(n-36) -3*a(n-37) -3*a(n-38) -2*a(n-39) -a(n-40) +a(n-42) +a(n-43)