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A183777 Half the number of (n+1) X 5 binary arrays with no 2 X 2 subblock having exactly 2 ones. 1
85, 567, 3435, 21935, 136843, 864671, 5431499, 34228999, 215374371, 1356329167, 8537916907, 53757639287, 338436138739, 2130795330527, 13415038654331, 84459841870343, 531746080445251, 3347809160159215, 21077341291331531 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A183782.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) + 26*a(n-2) - 98*a(n-3) - 188*a(n-4) + 580*a(n-5) + 392*a(n-6) - 1024*a(n-7) - 256*a(n-8) + 512*a(n-9).
Empirical g.f.: x*(85 + 142*x - 1610*x^2 - 1652*x^3 + 9404*x^4 + 4072*x^5 - 16544*x^6 - 3072*x^7 + 8192*x^8) / (1 - 5*x - 26*x^2 + 98*x^3 + 188*x^4 - 580*x^5 - 392*x^6 + 1024*x^7 + 256*x^8 - 512*x^9). - Colin Barker, Apr 04 2018
Empirical formula verified by Robert Israel, Jul 01 2018: see link.
EXAMPLE
Some solutions with a(1,1)=0 for 3 X 5:
0 1 0 0 0 0 1 0 0 1 0 1 1 1 0 0 0 0 0 0
1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 0 0 1 0 0
1 1 0 0 0 0 0 0 1 0 0 1 0 1 0 0 1 1 1 0
CROSSREFS
Cf. A183782.
Sequence in context: A264425 A250463 A339870 * A297599 A173470 A202009
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2011
STATUS
approved

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Last modified May 24 01:38 EDT 2024. Contains 372768 sequences. (Running on oeis4.)