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A204034 Number of (n+1)X4 0..1 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards 1
121, 603, 2928, 10505, 37642, 111578, 330509, 863435, 2254026, 5394662, 12906149, 29037224, 65337510, 140736855, 303340170, 634000207, 1326522462, 2717180447, 5573314419, 11270539628, 22825534613, 45808619416, 92067615036, 184020632660 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A204039

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +20*a(n-2) -98*a(n-3) -168*a(n-4) +1122*a(n-5) +674*a(n-6) -7970*a(n-7) -205*a(n-8) +39322*a(n-9) -13326*a(n-10) -142896*a(n-11) +86380*a(n-12) +395612*a(n-13) -325028*a(n-14) -850708*a(n-15) +867429*a(n-16) +1433880*a(n-17) -1752520*a(n-18) -1894178*a(n-19) +2759240*a(n-20) +1938970*a(n-21) -3430470*a(n-22) -1491450*a(n-23) +3380665*a(n-24) +795530*a(n-25) -2631230*a(n-26) -214060*a(n-27) +1599540*a(n-28) -65400*a(n-29) -744088*a(n-30) +104272*a(n-31) +255920*a(n-32) -56864*a(n-33) -61344*a(n-34) +17856*a(n-35) +9152*a(n-36) -3200*a(n-37) -640*a(n-38) +256*a(n-39)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A183448 A296127 A307798 * A183885 A036306 A014749

Adjacent sequences:  A204031 A204032 A204033 * A204035 A204036 A204037

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 09 2012

STATUS

approved

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Last modified January 20 10:55 EST 2022. Contains 350472 sequences. (Running on oeis4.)