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A252307 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7 1
1048, 1031, 1370, 1992, 3171, 5056, 7625, 12412, 19904, 30526, 49974, 80432, 123996, 203444, 327856, 506772, 832064, 1341188, 2076284, 3409168, 5493844, 8513612, 13975408, 22511348, 34911340, 57286320, 92228020, 143118508, 234743088 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 2 of A252305
LINKS
FORMULA
Empirical: a(n) = 11*a(n-3) -42*a(n-6) +64*a(n-9) -32*a(n-12) for n>21
EXAMPLE
Some solutions for n=4
..1..1..1..1..1..1....3..3..0..3..3..1....0..3..3..0..3..3....2..0..1..2..3..1
..2..0..1..2..0..1....3..2..2..3..2..2....1..0..2..1..0..2....3..0..0..0..0..0
..1..3..2..1..3..2....2..3..2..2..3..1....1..2..0..1..2..3....3..2..1..3..2..1
..1..1..1..1..1..1....3..3..0..3..3..1....0..3..3..0..3..3....2..3..1..2..0..1
CROSSREFS
Sequence in context: A249653 A056092 A280809 * A236273 A251375 A281033
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 16 2014
STATUS
approved

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Last modified February 29 19:20 EST 2024. Contains 370428 sequences. (Running on oeis4.)