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A252151 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7 1
1945, 1874, 1898, 2702, 4732, 8769, 16786, 32653, 64082, 126281, 249972, 496351, 987018, 1965441, 3918468, 7816699, 15602898, 31159889, 62243052, 124369539, 248564606, 496831189, 993205780, 1985726667, 3970284238, 7938763405 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A252157

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -2*a(n-2) +7*a(n-3) -18*a(n-4) +5*a(n-5) -8*a(n-6) +21*a(n-7) +34*a(n-8) -31*a(n-9) +16*a(n-10) -103*a(n-11) +63*a(n-12) -10*a(n-13) +58*a(n-14) -6*a(n-15) -28*a(n-16) +8*a(n-17) -24*a(n-18) +16*a(n-19) for n>27

EXAMPLE

Some solutions for n=4

..3..3..3..3....3..3..3..3....0..2..0..3....1..1..2..1....3..3..3..3

..2..0..2..3....0..2..0..2....2..0..2..2....0..2..0..3....3..1..0..3

..0..2..0..2....2..0..2..0....3..2..3..3....3..2..3..0....3..0..2..3

..2..0..2..0....0..2..0..2....3..2..3..3....1..0..1..1....3..1..0..3

..0..2..0..3....2..0..2..3....2..0..2..2....0..2..0..3....3..3..3..3

..2..0..3..1....3..3..3..3....0..2..0..3....3..2..3..0....3..0..1..3

CROSSREFS

Sequence in context: A201047 A269039 A300199 * A235003 A223464 A252062

Adjacent sequences:  A252148 A252149 A252150 * A252152 A252153 A252154

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 2014

STATUS

approved

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Last modified June 3 05:29 EDT 2020. Contains 334798 sequences. (Running on oeis4.)