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A302631 Number of nX4 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1
5, 17, 14, 33, 101, 248, 657, 1841, 4892, 13020, 35447, 95226, 255042, 688238, 1852413, 4976015, 13395869, 36053423, 96953152, 260865015, 701948030, 1888295155, 5080237927, 13668712238, 36773414080, 98934258153, 266178278368 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A302635.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) +9*a(n-3) -12*a(n-5) -13*a(n-6) +2*a(n-7) +17*a(n-8) +13*a(n-9) -6*a(n-10) -16*a(n-11) -12*a(n-12) +6*a(n-13) +12*a(n-14) +5*a(n-15) -8*a(n-16) -10*a(n-17) -4*a(n-18) +3*a(n-19) +3*a(n-20) +a(n-21) for n>25
EXAMPLE
Some solutions for n=5
..0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..1..0
..0..1..0..0. .0..1..1..0. .0..1..1..0. .0..1..0..1. .1..0..1..0
..0..1..0..1. .1..0..1..0. .1..0..1..0. .1..0..0..1. .1..0..1..0
..0..1..0..1. .1..0..1..0. .1..0..1..0. .1..0..1..0. .1..0..1..0
..0..1..1..0. .1..0..0..1. .1..1..0..0. .1..0..1..0. .1..0..0..1
CROSSREFS
Cf. A302635.
Sequence in context: A060829 A096896 A056850 * A303678 A303804 A304851
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2018
STATUS
approved

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Last modified March 29 08:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)