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A205938 Number of (n+1) X 3 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. 1
1776, 11028, 81864, 620988, 4601832, 34647764, 258956760, 1942182832, 14548134360, 109048169588, 816513313600, 6119001144252, 45844697097568, 343491408375096, 2573223557463040, 19280035339388884, 144450083231226680 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A205944.
LINKS
FORMULA
Empirical: a(n) = 20*a(n-2) +106*a(n-3) +1073*a(n-4) +1676*a(n-5) -3921*a(n-6) +2510*a(n-7) +10367*a(n-8) -39660*a(n-9) -93737*a(n-10) +67098*a(n-11) +1223861*a(n-12) -354734*a(n-13) -10343391*a(n-14) +12014472*a(n-15) +13924079*a(n-16) -59795244*a(n-17) +51740047*a(n-18) +57373456*a(n-19) -110979072*a(n-20) +74835622*a(n-21) -35991056*a(n-22) -22750738*a(n-23) +144074425*a(n-24) -153484616*a(n-25) +22971007*a(n-26) +78260016*a(n-27) -114414927*a(n-28) +63699940*a(n-29) +5571416*a(n-30) -148244590*a(n-31) +124206264*a(n-32) -55439888*a(n-33) -56510828*a(n-34) +78816744*a(n-35) -51200538*a(n-36) -18471918*a(n-37) +26953636*a(n-38) -21588268*a(n-39) -34226*a(n-40) +2404520*a(n-41) -4650695*a(n-42) -885160*a(n-43) -143680*a(n-44) -32966*a(n-45) -70777*a(n-46) -35254*a(n-47) +10119*a(n-48) +3744*a(n-49) -981*a(n-50) -4*a(n-51) for n>54.
EXAMPLE
Some solutions for n=4:
..1..1..1....0..3..3....3..2..1....0..1..3....1..1..2....1..1..1....0..0..2
..1..3..2....0..1..3....1..1..1....1..3..3....2..2..3....3..3..2....1..1..0
..0..0..3....3..2..0....3..3..2....1..3..3....2..2..2....1..0..3....1..1..0
..0..0..3....1..3..0....1..0..3....2..1..3....0..0..3....3..1..3....3..2..1
..3..2..1....2..2..1....2..1..1....2..2..0....2..1..0....0..1..1....0..3..0
CROSSREFS
Sequence in context: A185836 A047826 A143995 * A238307 A233953 A282404
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 01 2012
STATUS
approved

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Last modified April 22 00:17 EDT 2024. Contains 371886 sequences. (Running on oeis4.)