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A280809 Number of nX7 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
0, 1047, 24490, 133067, 521862, 1736603, 5219491, 14672850, 39446188, 102668319, 261032587, 651872767, 1605291205, 3909190755, 9432062891, 22579858190, 53688882185, 126896063565, 298328702932, 698005209403, 1626059718118 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 7 of A280810.
LINKS
FORMULA
Empirical: a(n) = 13*a(n-1) -72*a(n-2) +220*a(n-3) -400*a(n-4) +432*a(n-5) -256*a(n-6) +64*a(n-7) +6*a(n-8) -54*a(n-9) +183*a(n-10) -249*a(n-11) -51*a(n-12) +573*a(n-13) -672*a(n-14) +264*a(n-15) +33*a(n-16) +39*a(n-17) -156*a(n-18) +12*a(n-19) +225*a(n-20) -57*a(n-21) -390*a(n-22) +402*a(n-23) -19*a(n-24) -173*a(n-25) +66*a(n-26) +126*a(n-27) -156*a(n-28) +33*a(n-30) +93*a(n-31) -96*a(n-32) +2*a(n-33) +43*a(n-34) -45*a(n-35) -20*a(n-36) +74*a(n-37) -30*a(n-38) -18*a(n-39) +15*a(n-40) -3*a(n-41) -9*a(n-42) +15*a(n-43) -3*a(n-44) -3*a(n-45) -a(n-48) +a(n-49) for n>60
EXAMPLE
Some solutions for n=4
..0..1..0..0..1..0..1. .0..1..0..0..1..1..0. .0..0..1..0..0..1..0
..1..1..1..0..1..0..1. .0..1..0..1..0..1..1. .1..1..0..1..0..1..0
..0..0..1..0..1..0..1. .1..0..0..1..0..0..0. .0..1..0..1..0..1..0
..1..1..0..1..0..0..1. .1..1..1..0..1..1..0. .1..1..0..1..0..1..1
CROSSREFS
Cf. A280810.
Sequence in context: A226114 A249653 A056092 * A252307 A236273 A251375
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 08 2017
STATUS
approved

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Last modified February 25 06:40 EST 2024. Contains 370310 sequences. (Running on oeis4.)