A266126 Number of n X 3 integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself.

4, 25, 77, 385, 2099, 9083, 48188, 249446, 1166325, 6288299, 31791039, 153857132, 834409385, 4178055126, 20594948568, 111887135749, 558869714981, 2784252991713, 15113219048778, 75548474928693, 378923024757908

Offset: 1

Author

R. H. Hardin, Dec 21 2015

Keywords

• nonn

Comments

Column 3 of A266131.

Examples

			Some solutions for n=4
..1..1..1....1..1..0....0..2..0....2..1..0....0..0..0....0..1..1....0..2..1
..0..0..1....1..0..1....1..0..1....1..1..1....0..2..0....1..0..1....0..0..1
..0..2..0....2..1..1....1..1..2....2..0..1....1..0..1....1..1..2....0..2..0
..1..0..0....2..1..0....0..1..2....1..1..0....0..2..0....2..1..0....0..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A266131.

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +205*a(n-3) -120*a(n-4) -258*a(n-5) -10662*a(n-6) -1620*a(n-7) +5336*a(n-8) +88936*a(n-9) +201296*a(n-10) +58144*a(n-11) +86672*a(n-12) -1097792*a(n-13) -831920*a(n-14) -2968704*a(n-15) -782336*a(n-16) -723152*a(n-17) +635968*a(n-18) +3427456*a(n-19) +337216*a(n-20) -204224*a(n-21) -289664*a(n-22) -453120*a(n-23) +20992*a(n-24) -1536*a(n-25) -12288*a(n-26) for n>27.