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A204861 Number of (n+2)X4 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly two different ways, and new values 0..1 introduced in row major order 1
382, 1648, 7127, 31034, 136899, 603605, 2660367, 11721609, 51702644, 227902203, 1004799769, 4430100363, 19531105570, 86110306240, 379643708799, 1673789364704, 7379441106496, 32534731009926, 143440092995732 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A204867

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +7*a(n-2) +21*a(n-3) +a(n-4) -74*a(n-5) -162*a(n-6) +138*a(n-7) -18*a(n-8) +1187*a(n-9) -2509*a(n-10) -1249*a(n-11) +375*a(n-12) -3916*a(n-13) +29438*a(n-14) -20835*a(n-15) +21040*a(n-16) -41934*a(n-17) -21760*a(n-18) +100360*a(n-19) -54423*a(n-20) +171105*a(n-21) -190049*a(n-22) -55439*a(n-23) -103559*a(n-24) +4935*a(n-25) +72883*a(n-26) -32323*a(n-27) +95561*a(n-28) -221835*a(n-29) +320810*a(n-30) -176564*a(n-31) +95261*a(n-32) +33740*a(n-33) -115048*a(n-34) +86489*a(n-35) -210476*a(n-36) +35609*a(n-37) -117190*a(n-38) +191186*a(n-39) +95961*a(n-40) -27689*a(n-41) +89312*a(n-42) -83490*a(n-43) +9205*a(n-44) +61964*a(n-45) -55123*a(n-46) +33185*a(n-47) -16169*a(n-48) -5814*a(n-49) +12737*a(n-50) -3837*a(n-51) -410*a(n-52) -140*a(n-53) -740*a(n-54) +184*a(n-55) +104*a(n-56) -24*a(n-57) for n>58

EXAMPLE

Some solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A201800 A172848 A214896 * A015861 A072385 A045122

Adjacent sequences:  A204858 A204859 A204860 * A204862 A204863 A204864

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 20 2012

STATUS

approved

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Last modified June 21 17:44 EDT 2021. Contains 345365 sequences. (Running on oeis4.)