[go: up one dir, main page]

login
A235278
Number of (n+1) X (8+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).
1
15520, 19060, 23000, 31504, 41704, 64168, 93992, 160888, 260680, 487960, 867560, 1744024, 3354184, 7125208, 14577512, 32303128, 69232840, 158470360, 351398120, 824485144, 1873576264, 4478463448, 10354825832, 25091436568, 58718701000
OFFSET
1,1
COMMENTS
Column 8 of A235280.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +15*a(n-2) -15*a(n-3) -80*a(n-4) +80*a(n-5) +180*a(n-6) -180*a(n-7) -144*a(n-8) +144*a(n-9).
EXAMPLE
Some solutions for n=5:
1 2 0 3 1 4 1 2 1 1 3 0 4 0 4 1 4 1
4 0 3 1 4 2 4 0 4 4 1 3 2 3 2 4 2 4
1 2 0 3 1 4 1 2 1 1 3 0 4 0 4 1 4 1
4 0 3 1 4 2 4 0 4 3 0 2 1 2 1 3 1 3
1 2 0 3 1 4 1 2 1 1 3 0 4 0 4 1 4 1
4 0 3 1 4 2 4 0 4 3 0 2 1 2 1 3 1 3
CROSSREFS
Sequence in context: A035920 A342310 A201344 * A329769 A100973 A247692
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2014
STATUS
approved