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A209042 Number of n X 3 0..3 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it. 1
36, 1300, 47700, 1752148, 64369764, 2364812680, 86878417604, 3191736905988, 117257942776700, 4307819083344444, 158260539240359944, 5814171346741659592, 213600867349885236600, 7847262801829583566600, 288292525423375500733688 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A209047.

LINKS

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

Robert Israel, Maple-assisted proof of empirical formula

FORMULA

Empirical: a(n) = 23*a(n-1) +491*a(n-2) +570*a(n-3) -2219*a(n-4) -7882*a(n-5) -12517*a(n-6) -6376*a(n-7) -1205*a(n-8) -6747*a(n-9) +4080*a(n-10) +7811*a(n-11) -4675*a(n-12) +1790*a(n-13) +2576*a(n-14) -2905*a(n-15) +513*a(n-16) +621*a(n-17) -27*a(n-18) -81*a(n-19).

Formula confirmed by Robert Israel, Apr 03 2018 (see link).

EXAMPLE

Some solutions for n=4

..0..1..0....0..1..2....2..1..2....2..0..1....1..0..2....1..3..0....1..0..1

..3..3..2....3..3..0....3..0..2....0..2..0....3..2..1....2..1..3....0..1..3

..1..3..1....0..1..1....2..0..0....1..2..2....1..0..3....0..1..0....1..2..1

..2..3..3....3..3..1....1..3..0....3..0..0....3..0..1....1..2..0....0..2..3

CROSSREFS

Cf. A209047.

Sequence in context: A009980 A041613 A255821 * A283729 A203333 A226772

Adjacent sequences:  A209039 A209040 A209041 * A209043 A209044 A209045

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 04 2012

STATUS

approved

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Last modified November 14 04:44 EST 2019. Contains 329108 sequences. (Running on oeis4.)