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A253453 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically. 1
8501, 15220, 19254, 26831, 44242, 83003, 170184, 373130, 864720, 2104994, 5356824, 14174330, 38750880, 108728594, 311157864, 903437930, 2650262640, 7830705794, 23251973304, 69275651930, 206866440000, 618678308594, 1852192923144 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>9.
Empirical: a(n) = 529*3^(n-3) + 1832*2^(n-1) + 10087 for n>6.
Empirical g.f.: x*(8501 - 35786*x + 21445*x^2 + 27721*x^3 + 3730*x^4 - 2832*x^5 - 2158*x^6 - 393*x^7 - 54*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - Colin Barker, Dec 13 2018
EXAMPLE
Some solutions for n=4:
..1..2..2..2..2..2....0..1..2..1..2..1....0..1..0..1..1..0....1..1..1..0..0..0
..1..1..1..1..1..1....1..1..2..1..2..1....1..1..0..1..1..0....1..1..1..0..0..0
..1..0..0..0..0..0....2..1..2..1..2..1....2..1..0..1..1..0....2..2..2..1..1..1
..2..0..0..0..0..0....2..0..1..0..1..0....2..1..0..1..1..0....2..2..2..1..1..1
..2..0..0..0..0..1....2..0..1..0..1..0....2..1..0..1..1..1....0..0..0..0..1..2
CROSSREFS
Column 5 of A253456.
Sequence in context: A322160 A253499 A253492 * A348605 A260988 A188214
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 01 2015
STATUS
approved

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Last modified March 4 01:40 EST 2024. Contains 370522 sequences. (Running on oeis4.)