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A301822
Number of nX7 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.
1
8, 128, 968, 6653, 47363, 333335, 2341241, 16471479, 115975709, 816674776, 5750906471, 40498618037, 285206498639, 2008567595662, 14145438133381, 99620184969372, 701582362197999, 4940946394826023, 34796990566402966
OFFSET
1,1
COMMENTS
Column 7 of A301823.
LINKS
FORMULA
Empirical: a(n) = 30*a(n-1) -418*a(n-2) +3654*a(n-3) -22669*a(n-4) +106606*a(n-5) -395403*a(n-6) +1186422*a(n-7) -2928707*a(n-8) +6014938*a(n-9) -10354804*a(n-10) +15013356*a(n-11) -18384098*a(n-12) +19034892*a(n-13) -16660310*a(n-14) +12301356*a(n-15) -7624215*a(n-16) +3923202*a(n-17) -1635354*a(n-18) +519982*a(n-19) -103769*a(n-20) -2026*a(n-21) +11017*a(n-22) -4610*a(n-23) +1059*a(n-24) -138*a(n-25) +8*a(n-26) for n>28
EXAMPLE
Some solutions for n=5
..0..0..0..1..1..0..0. .0..0..1..1..1..1..0. .0..0..1..1..0..0..0
..1..1..0..1..0..1..1. .0..1..0..0..1..0..0. .0..0..1..0..1..0..0
..1..0..1..1..0..1..0. .1..1..0..1..1..1..0. .0..0..0..1..1..0..0
..0..0..1..0..1..0..0. .1..0..0..0..1..0..1. .1..1..0..0..1..1..1
..1..1..0..0..1..1..1. .1..1..1..0..0..1..1. .1..1..1..0..0..1..1
CROSSREFS
Cf. A301823.
Sequence in context: A302268 A302967 A302071 * A302810 A061549 A303471
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 27 2018
STATUS
approved