A229386 Number of n X 2 0..3 arrays of the sum of the corresponding element, the element to the east and the element to the south in a larger (n+1) X 3 0..1 array.

14, 128, 1064, 8592, 68672, 546752, 4346752, 34537984, 274370048, 2179421184, 17311399936, 137504870400, 1092199604224, 8675313975296, 68907755405312, 547332071161856, 4347440512892928, 34531574742253568, 274283140633591808

Offset: 1

Author

R. H. Hardin, Sep 21 2013

Keywords

• nonn

Examples

			Some solutions for n=3:
  0 0   1 2   3 2   0 1   1 1   2 2   2 0   2 1   2 3   1 1
  1 0   3 1   1 1   1 0   1 2   1 2   1 0   0 1   2 3   3 3
  2 1   2 1   2 1   1 1   1 0   0 2   1 2   2 1   3 1   3 3
		

Links

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

Crossrefs

Column 2 of A229392.

Formula

Empirical: a(n) = 12*a(n-1) - 36*a(n-2) + 32*a(n-3) - 16*a(n-4).

Empirical g.f.: 2*x*(1 - 2*x)*(7 - 6*x + 4*x^2) / (1 - 12*x + 36*x^2 - 32*x^3 + 16*x^4). - Colin Barker, Sep 14 2018