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A297522
Number of 4Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s.
1
1, 24, 177, 624, 2610, 15896, 85843, 402072, 1970884, 10281752, 52457558, 260911506, 1310325200, 6651660023, 33617677893, 169149591947, 852752626610, 4307076050513, 21735155415610, 109599311945494, 552867513790810
OFFSET
1,2
COMMENTS
Row 4 of A297519.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +7*a(n-2) +30*a(n-3) +190*a(n-4) +135*a(n-5) -397*a(n-6) -744*a(n-7) -3268*a(n-8) -2810*a(n-9) +6340*a(n-10) +2928*a(n-11) -2154*a(n-12) +11260*a(n-13) -3923*a(n-14) -40330*a(n-15) -10049*a(n-16) +42471*a(n-17) +30552*a(n-18) -645*a(n-19) -17700*a(n-20) -17696*a(n-21) +2847*a(n-22) +15106*a(n-23) -2542*a(n-24) -5927*a(n-25) +11368*a(n-26) +2122*a(n-27) -2117*a(n-28) +212*a(n-29) -4*a(n-30) -94*a(n-31)
EXAMPLE
Some solutions for n=7
..0..0..0..0..1..0..1. .0..0..1..1..0..0..1. .1..0..0..0..0..1..1
..0..0..0..0..1..1..0. .1..0..0..0..0..1..0. .1..1..0..0..0..0..0
..0..0..0..0..0..0..0. .0..1..0..1..0..0..0. .1..0..0..0..0..0..0
..1..1..0..0..0..0..0. .1..0..1..1..0..1..1. .0..0..1..1..0..0..0
CROSSREFS
Cf. A297519.
Sequence in context: A375330 A209986 A372521 * A165187 A052761 A371158
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 31 2017
STATUS
approved