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A195974 Number of n X 4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,1,3,4 for x=0,1,2,3,4. 1
5, 23, 36, 67, 133, 256, 455, 931, 1830, 3565, 7001, 13872, 27433, 54401, 108164, 215285, 428869, 855426, 1707759, 3411577, 6819860, 13640635, 27294311, 54635604, 109402661, 219127235, 438997334, 879659285, 1762952379, 3533677212 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 3's, every 4 is next to 4 4's.
Column 4 of A195978.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -7*a(n-2) +13*a(n-3) -17*a(n-4) +9*a(n-5) -7*a(n-6) -11*a(n-7) +28*a(n-8) -20*a(n-9) +37*a(n-10) -7*a(n-11) +11*a(n-13) -41*a(n-14) +14*a(n-15) -32*a(n-16) +19*a(n-18) -14*a(n-19) +30*a(n-20) -10*a(n-21) +9*a(n-22) +7*a(n-23) -9*a(n-24) +10*a(n-25) -11*a(n-26) +3*a(n-28) -4*a(n-29) +a(n-30) -2*a(n-31) -2*a(n-32).
EXAMPLE
Some solutions for n=5:
..2..1..0..1....2..1..1..2....2..1..1..0....2..1..0..1....0..1..1..1
..1..1..0..1....1..0..0..1....1..0..1..1....1..1..1..2....1..1..0..0
..0..1..1..1....2..1..1..2....1..0..1..1....0..0..1..2....1..1..1..1
..0..1..1..0....2..1..1..2....1..1..1..0....1..1..1..1....0..0..1..1
..0..1..1..0....1..0..0..1....0..1..1..0....2..1..0..0....1..1..1..0
CROSSREFS
Sequence in context: A329160 A337436 A050906 * A098421 A371622 A044447
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2011
STATUS
approved

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Last modified July 21 21:26 EDT 2024. Contains 374475 sequences. (Running on oeis4.)