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A203919 Number of (n+2)X6 0..1 arrays with every 3X3 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..1 introduced in row major order 1
5000, 21632, 75272, 262088, 916658, 3220722, 11309768, 39783200, 139846088, 491348552, 1725311282, 6060344418, 21285209138, 74766898208, 262625483282, 922568228082, 3240635377778, 11383319836800, 39985279887938 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A203923

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +4*a(n-2) +21*a(n-4) -44*a(n-5) +77*a(n-6) +158*a(n-7) -83*a(n-8) -645*a(n-9) +64*a(n-10) -2301*a(n-11) -3155*a(n-12) +1580*a(n-13) +6476*a(n-14) +55*a(n-15) +15516*a(n-16) +19296*a(n-17) -747*a(n-18) -810*a(n-19) -5913*a(n-20) -75627*a(n-21) -49815*a(n-22) +27054*a(n-23) -243*a(n-24) +19926*a(n-25) +11664*a(n-26) +10935*a(n-27) -6561*a(n-28) for n>29

EXAMPLE

Some solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A157367 A200910 A035901 * A035787 A108011 A018188

Adjacent sequences:  A203916 A203917 A203918 * A203920 A203921 A203922

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 07 2012

STATUS

approved

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Last modified June 25 03:00 EDT 2022. Contains 354835 sequences. (Running on oeis4.)