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Search: id:A165374
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| A165374 |
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Number of slanted nX5 (i=1..n)X(j=i..5+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, and 4 in the lower right corner |
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+0
1
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| 105, 1622, 11960, 63740, 272548, 993780, 3239860, 9743508, 27593908, 74632788, 194702068, 493466004, 1221540916, 2965389012, 7081701748, 16678011924, 38810916532, 89383135572, 203992087540, 461842419348, 1038214750516
(list; graph; listen)
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OFFSET
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2,1
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LINKS
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R. H. Hardin, Table of n, a(n) for n=2..48
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FORMULA
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Empirical: a(n)=8*a(n-1)-25*a(n-2)+38*a(n-3)-28*a(n-4)+8*a(n-5) for n>=11
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EXAMPLE
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Some solutions for n=3
...1.2.2.2.2.......1.1.1.2.2.......1.1.2.2.2.......1.1.1.2.2....
.....3.3.3.2.2.......1.1.1.2.4.......1.3.3.2.2.......1.1.1.2.2..
.......3.2.2.2.4.......3.3.2.4.4.......3.3.4.4.4.......3.1.2.4.4
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...1.1.2.2.2.......1.1.1.2.2.......1.1.1.1.2.......1.1.2.2.2....
.....1.1.1.1.1.......1.2.2.2.2.......1.1.1.2.2.......1.1.2.2.2..
.......3.3.3.3.4.......3.3.2.4.4.......3.3.3.4.4.......3.4.4.4.4
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...1.1.2.2.2.......1.1.1.3.2.......1.1.2.2.2.......1.1.2.2.2....
.....1.2.3.2.4.......3.3.3.2.2.......2.2.2.4.4.......2.2.2.4.4..
.......3.3.3.4.4.......3.2.2.4.4.......3.4.4.4.4.......3.2.2.4.4
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CROSSREFS
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Sequence in context: A165382 A051015 A076377 this_sequence A024198 A027788 A112497
Adjacent sequences: A165371 A165372 A165373 this_sequence A165375 A165376 A165377
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net) Sep 17 2009
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