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A208710 Number of 3Xn 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors 1
4, 32, 196, 1268, 8128, 52184, 334948, 2149988, 13800400, 88582472, 568596052, 3649722932, 23426960800, 150373741496, 965223885508, 6195610615940, 39768587869168, 255267911291816, 1638522010126516, 10517398618896212 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A208709

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) +9*a(n-2) +a(n-3) -2*a(n-4)

EXAMPLE

Some solutions for n=4

..0..0..0..1....0..0..1..0....0..1..0..1....0..1..1..0....0..0..1..0

..0..1..0..1....0..0..1..1....0..1..0..0....1..0..0..1....1..1..1..0

..1..0..0..1....1..0..0..0....0..1..1..0....1..0..1..1....0..1..0..0

CROSSREFS

Sequence in context: A222507 A018215 A099133 * A043018 A002012 A240408

Adjacent sequences:  A208707 A208708 A208709 * A208711 A208712 A208713

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 01 2012

STATUS

approved

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Last modified October 20 14:08 EDT 2014. Contains 248334 sequences.