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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.
1
4, 25, 77, 385, 2099, 9083, 48188, 249446, 1166325, 6288299, 31791039, 153857132, 834409385, 4178055126, 20594948568, 111887135749, 558869714981, 2784252991713, 15113219048778, 75548474928693, 378923024757908
OFFSET
1,1
COMMENTS
Column 3 of A266131.
LINKS
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.
EXAMPLE
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
CROSSREFS
Cf. A266131.
Sequence in context: A302821 A125309 A273361 * A303514 A041991 A027764
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 21 2015
STATUS
approved