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A220801 Sum of neighbor maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and vertical neighbors in a random 0..3 nX2 array 1
2, 16, 48, 256, 928, 4096, 15820, 65536, 259584, 1048576, 4182016, 16777216, 67051520, 268435456, 1073476576, 4294967296, 17178689536, 68719476736, 274872664064, 1099511627776, 4398023442432, 17592186044416, 70368643424320 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A220805

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +8*a(n-2) -32*a(n-3) -16*a(n-4) +64*a(n-5) +44*a(n-8) -176*a(n-9) -352*a(n-10) +1408*a(n-11) +704*a(n-12) -2816*a(n-13) -688*a(n-16) +2752*a(n-17) +5504*a(n-18) -22016*a(n-19) -11008*a(n-20) +44032*a(n-21) +4672*a(n-24) -18688*a(n-25) -37376*a(n-26) +149504*a(n-27) +74752*a(n-28) -299008*a(n-29) -14336*a(n-32) +57344*a(n-33) +114688*a(n-34) -458752*a(n-35) -229376*a(n-36) +917504*a(n-37) +16384*a(n-40) -65536*a(n-41) -131072*a(n-42) +524288*a(n-43) +262144*a(n-44) -1048576*a(n-45)

EXAMPLE

Some solutions for n=3

..0..0....0..0....0..0....0..0....1..0....0..0....0..1....0..1....0..1....1..1

..0..1....1..1....0..1....0..0....1..0....1..1....0..1....1..0....1..1....0..0

..0..1....0..0....1..0....1..0....1..0....1..0....1..0....0..1....0..1....1..1

CROSSREFS

Sequence in context: A275032 A295533 A220173 * A220250 A192388 A162442

Adjacent sequences: A220798 A220799 A220800 * A220802 A220803 A220804

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 21 2012

STATUS

approved

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Last modified December 3 05:56 EST 2022. Contains 358512 sequences. (Running on oeis4.)