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 A250313 Number of length n+2 0..1 arrays with the sum of second differences squared multiplied by some arrangement of +-1 equal to zero. 1
 2, 8, 8, 24, 42, 104, 212, 464, 950, 1968, 3984, 8072, 16226, 32600, 65324, 130848, 261870, 524000, 1048232, 2096792, 4193882, 8388168, 16776708, 33553904, 67108262, 134217104, 268434752, 536870184, 1073741010, 2147482808, 4294966364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 3*a(n-4) + 3*a(n-5) - 2*a(n-6). Empirical g.f.: 2*x*(1 + x - 8*x^2 + 6*x^3 + 6*x^4 - 2*x^5) / ((1 - x)^3*(1 + x)^2*(1 - 2*x)). - Colin Barker, Nov 12 2018 EXAMPLE Some solutions for n=6: ..1....0....0....0....1....0....0....1....1....0....1....0....0....1....1....0 ..1....0....0....1....1....0....1....1....0....0....0....1....1....0....0....0 ..0....0....0....0....1....1....0....0....1....0....0....0....0....1....1....1 ..0....0....1....0....0....1....1....1....0....1....1....1....0....1....1....1 ..1....1....1....0....0....1....0....0....1....1....0....1....1....0....0....1 ..0....0....1....0....1....1....0....0....0....1....0....1....1....0....0....0 ..0....1....0....1....1....1....1....1....1....1....0....1....0....1....0....1 ..0....1....0....0....1....1....0....1....0....1....1....0....1....0....1....1 CROSSREFS Column 1 of A250320. Sequence in context: A093907 A116471 A146749 * A180825 A230708 A230739 Adjacent sequences:  A250310 A250311 A250312 * A250314 A250315 A250316 KEYWORD nonn AUTHOR R. H. Hardin, Nov 18 2014 STATUS approved

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Last modified December 15 14:37 EST 2019. Contains 329999 sequences. (Running on oeis4.)