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A236721 Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock equal 1
81, 211, 550, 1517, 4227, 12072, 34817, 101881, 300694, 896941, 2695583, 8170608, 24926541, 76581709, 236571526, 735006969, 2293934715, 7192276024, 22632537625, 71477629985, 226390525302, 719056784565, 2288987001383, 7302243641824 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A236728

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) +12*a(n-2) -177*a(n-3) +89*a(n-4) +1806*a(n-5) -2318*a(n-6) -9698*a(n-7) +16880*a(n-8) +30048*a(n-9) -63832*a(n-10) -54640*a(n-11) +140752*a(n-12) +54864*a(n-13) -184064*a(n-14) -22784*a(n-15) +135936*a(n-16) -4480*a(n-17) -48640*a(n-18) +5120*a(n-19) +5120*a(n-20)

EXAMPLE

Some solutions for n=7

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

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A236884 A236728 A236877 * A255110 A062532 A075730

Adjacent sequences:  A236718 A236719 A236720 * A236722 A236723 A236724

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 30 2014

STATUS

approved

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Last modified August 5 07:33 EDT 2020. Contains 336209 sequences. (Running on oeis4.)