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A283518
Number of nX4 0..1 arrays with no 1 equal to more than three of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements.
1
0, 5, 270, 5988, 113984, 2032993, 34279720, 558718061, 8877675769, 138361189406, 2123703646624, 32194034680888, 483025956805625, 7184039753675004, 106048960050497877, 1555282253332563953, 22678862678133637034
OFFSET
1,2
COMMENTS
Column 4 of A283522.
LINKS
FORMULA
Empirical: a(n) = 24*a(n-1) -18*a(n-2) -1861*a(n-3) -5151*a(n-4) +53448*a(n-5) +497137*a(n-6) +2079267*a(n-7) +5467509*a(n-8) +9711068*a(n-9) +11318400*a(n-10) +6922557*a(n-11) -2098502*a(n-12) -9203736*a(n-13) -9732957*a(n-14) -4676754*a(n-15) -588741*a(n-16) +5212512*a(n-17) -814070*a(n-18) +8518395*a(n-19) -12331164*a(n-20) +17284529*a(n-21) -23451075*a(n-22) +25895262*a(n-23) -26065323*a(n-24) +23525073*a(n-25) -18903846*a(n-26) +13767022*a(n-27) -9035040*a(n-28) +5322504*a(n-29) -2815583*a(n-30) +1324926*a(n-31) -547305*a(n-32) +195707*a(n-33) -59001*a(n-34) +14325*a(n-35) -2634*a(n-36) +339*a(n-37) -27*a(n-38) +a(n-39) for n>43
EXAMPLE
Some solutions for n=4
..1..0..0..0. .0..0..1..0. .0..0..0..1. .0..1..1..1. .0..1..1..0
..0..0..1..1. .1..0..1..0. .0..1..1..1. .0..0..1..1. .1..1..1..1
..1..1..1..0. .1..0..1..1. .0..1..0..1. .1..1..1..0. .0..1..0..0
..1..1..0..1. .0..1..1..1. .1..1..1..0. .0..0..1..1. .0..1..0..0
CROSSREFS
Cf. A283522.
Sequence in context: A180820 A140001 A329610 * A153322 A326321 A234324
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 09 2017
STATUS
approved