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A235407 Number of (n+1)X(2+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing rowwise and nonincreasing columnwise 1
44, 172, 704, 2302, 7617, 21707, 62070, 160219, 413728, 994013, 2386992, 5442827, 12403299, 27224435, 59728771, 127521907, 272186909, 569643759, 1192017901, 2459436721, 5074257282, 10364928156, 21172231949, 42946541188, 87117681967 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A235413

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +15*a(n-2) -78*a(n-3) -84*a(n-4) +696*a(n-5) +112*a(n-6) -3760*a(n-7) +1218*a(n-8) +13704*a(n-9) -8862*a(n-10) -35508*a(n-11) +32060*a(n-12) +67024*a(n-13) -76668*a(n-14) -92568*a(n-15) +131079*a(n-16) +91860*a(n-17) -164969*a(n-18) -61582*a(n-19) +153888*a(n-20) +22296*a(n-21) -105420*a(n-22) +2424*a(n-23) +51632*a(n-24) -7808*a(n-25) -17136*a(n-26) +4320*a(n-27) +3456*a(n-28) -1152*a(n-29) -320*a(n-30) +128*a(n-31)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A072428 A010023 A084026 * A006563 A159033 A238249

Adjacent sequences:  A235404 A235405 A235406 * A235408 A235409 A235410

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 10 2014

STATUS

approved

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Last modified August 23 22:45 EDT 2019. Contains 326254 sequences. (Running on oeis4.)