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 A183936 Number of strings of n numbers x(i) in -1..1 with sums of x(i) and of x(i)*x(i+1) both zero 1
 1, 1, 3, 7, 21, 45, 121, 261, 723, 1723, 5087, 13091, 38641, 101993, 297423, 800187, 2324961, 6378601, 18544345, 51670725, 150172263, 422922591, 1228542913, 3488055573, 10134018375, 28962183951, 84203226523, 241924870591 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Column 1 of A183944 LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 EXAMPLE All solutions for n=4 ..1....0....0...-1...-1....1....0 ..0....0....1....0....0....0...-1 .-1....0....0....0....1....0....0 ..0....0...-1....1....0...-1....1 CROSSREFS Sequence in context: A119959 A329114 A018712 * A027151 A219589 A092203 Adjacent sequences: A183933 A183934 A183935 * A183937 A183938 A183939 KEYWORD nonn AUTHOR R. H. Hardin Jan 08 2011 STATUS approved

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Last modified October 1 02:41 EDT 2023. Contains 365812 sequences. (Running on oeis4.)