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A179008
T(n,k) is the base-2 logarithm of the number of n X k binary arrays with no adjacent elements having the mod 2 sum of their neighbors equal.
1
1, 1, 1, 2, 3, 2, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 3, 1, 2, 1, 2, 5, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 4, 1, 5, 1, 4, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 7, 2, 1, 2, 1, 2, 1, 3, 1, 5, 3, 1, 1, 3, 5, 1, 3, 1, 1, 1, 3, 1, 1, 1, 7, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2
OFFSET
1,4
COMMENTS
T(n,k) is apparently the number of bits (not necessarily arbitrarily chosen ones) whose values may be chosen independently, the rest then being determined.
LINKS
FORMULA
Empirical: Let x = gcd(k+1,2^k).
T(n,k) = gcd(n+1,k+1) for k or n even;
T(n,k) = gcd(n+1,k+1)-1 for k and n odd with (n+1-x) modulo (2x) = 0;
T(n,k) = gcd(n+1,k+1) otherwise.
EXAMPLE
Table starts
1 1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1 1
1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1
2 1 3 1 2 1 4 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1
1 1 1 5 1 1 1 1 5 1 1 1 1 5 1 1 1 1 5 1 1 1 1 5 1 1 1 1 5 1
1 3 2 1 5 1 2 3 1 1 6 1 1 3 2 1 5 1 2 3 1 1 6 1 1 3 2 1 5 1
1 1 1 1 1 7 1 1 1 1 1 1 7 1 1 1 1 1 1 7 1 1 1 1 1 1 7 1 1 1
2 1 4 1 2 1 7 1 2 1 4 1 2 1 8 1 2 1 4 1 2 1 7 1 2 1 4 1 2 1
1 3 1 1 3 1 1 9 1 1 3 1 1 3 1 1 9 1 1 3 1 1 3 1 1 9 1 1 3 1
1 1 2 5 1 1 2 1 9 1 2 1 1 5 2 1 1 1 10 1 1 1 2 5 1 1 2 1 9 1
1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1
2 3 3 1 6 1 4 3 2 1 11 1 2 3 4 1 6 1 3 3 2 1 12 1 2 3 3 1 6 1
1 1 1 1 1 1 1 1 1 1 1 13 1 1 1 1 1 1 1 1 1 1 1 1 13 1 1 1 1 1
1 1 2 1 1 7 2 1 1 1 2 1 13 1 2 1 1 1 2 7 1 1 2 1 1 1 14 1 1 1
1 3 1 5 3 1 1 3 5 1 3 1 1 15 1 1 3 1 5 3 1 1 3 5 1 3 1 1 15 1
2 1 4 1 2 1 8 1 2 1 4 1 2 1 15 1 2 1 4 1 2 1 8 1 2 1 4 1 2 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 17 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 3 2 1 5 1 2 9 1 1 6 1 1 3 2 1 17 1 2 3 1 1 6 1 1 9 2 1 5 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 19 1 1 1 1 1 1 1 1 1 1 1 1
2 1 3 5 2 1 4 1 10 1 3 1 2 5 4 1 2 1 19 1 2 1 4 5 2 1 3 1 10 1
1 3 1 1 3 7 1 3 1 1 3 1 7 3 1 1 3 1 1 21 1 1 3 1 1 3 7 1 3 1
1 1 2 1 1 1 2 1 1 11 2 1 1 1 2 1 1 1 2 1 21 1 2 1 1 1 2 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 23 1 1 1 1 1 1 1 1
2 3 4 1 6 1 7 3 2 1 12 1 2 3 8 1 6 1 4 3 2 1 23 1 2 3 4 1 6 1
1 1 1 5 1 1 1 1 5 1 1 1 1 5 1 1 1 1 5 1 1 1 1 25 1 1 1 1 5 1
....
Some solutions for 10 X 10:
1 1 0 0 1 1 0 1 0 0 0 0 1 0 0 1 1 1 0 0
1 0 1 0 1 0 0 1 1 1 1 1 1 1 0 1 1 1 0 0
0 1 1 0 0 0 0 0 1 1 1 1 1 0 0 1 1 1 1 1
0 0 0 0 1 1 0 1 0 1 1 1 1 0 0 0 0 1 1 1
1 1 0 1 0 1 1 0 0 1 0 0 0 0 0 0 0 1 1 1
1 0 0 1 1 1 1 1 1 0 0 1 0 0 1 0 0 0 0 0
0 0 0 0 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 0
1 1 0 1 0 1 0 0 1 1 0 1 0 1 0 0 1 1 1 1
0 1 1 0 0 1 0 1 0 1 0 0 1 1 1 0 1 1 1 0
0 1 1 1 1 0 0 1 1 0 1 0 0 1 0 0 1 1 1 0
All solutions for 10 X 9:
1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
1 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0
0 1 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1
1 0 0 0 1 0 0 0 1 0 1 0 0 0 0 0 1 0
0 1 0 0 0 0 0 1 0 1 0 0 0 1 0 0 0 1
1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 1 0
0 1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 1
1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1
All solutions for 5 X 4:
0 0 0 0 0 0 0 0
0 1 0 1 1 0 1 0
0 0 1 0 0 1 0 0
0 1 0 1 1 0 1 0
0 0 0 0 0 0 0 0
CROSSREFS
Sequence in context: A083475 A211994 A122402 * A255252 A174985 A008406
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jan 03 2011
STATUS
approved