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A139007 Number of n X n symmetric binary matrices containing no more than two 1s in any 2 X 2 sub-block. 2
1, 2, 5, 25, 205, 2849, 66677, 2633485, 175143651, 19638725775, 3710411382331, 1181447019186469, 633957805831439213, 573281808520220290885, 873645764409736229092874, 2243689725607702437916265557 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
R. H. Hardin, May 31 2008, Table of n, a(n) for n = 0..20
CROSSREFS
Sequence in context: A324263 A049650 A191506 * A015486 A191951 A356674
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 31 2008
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)