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 A199707 Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two neighbors equal. 1
 14, 200, 892, 2734, 6504, 13324, 24394, 41344, 65788, 99858, 145596, 205612, 282386, 379036, 498440, 644218, 819692, 1028960, 1275766, 1564716, 1899968, 2286630, 2729288, 3233528, 3804374, 4447920, 5169588, 5975974, 6872944, 7867572, 8966146 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 5 of A199704. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n)=2*a(n-1)-a(n-3)-2*a(n-5)+2*a(n-6)+a(n-8)-2*a(n-10)+a(n-11). Empirical g.f.: 2*x*(7 + 86*x + 246*x^2 + 482*x^3 + 618*x^4 + 618*x^5 + 426*x^6 + 222*x^7 + 47*x^8 + 8*x^9) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - Colin Barker, May 16 2018 EXAMPLE Some solutions for n=5: .-5...-1...-3...-4....4....1...-3...-1....5....0...-4....1....4....0....2....1 ..0....0....1...-3....1....3....1....2...-3...-2...-3...-2....0....2....3...-3 .-3...-4....2....3...-3....1...-4...-1...-1....5....1...-3...-3....4...-5....5 ..3....2...-5....1...-4...-5....2....1...-3...-2....2....4....1...-4....4....1 ..5....3....5....3....2....0....4...-1....2...-1....4....0...-2...-2...-4...-4 CROSSREFS Cf. A199704. Sequence in context: A124239 A041366 A051817 * A222586 A221830 A068769 Adjacent sequences: A199704 A199705 A199706 * A199708 A199709 A199710 KEYWORD nonn AUTHOR R. H. Hardin, Nov 09 2011 STATUS approved

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Last modified September 19 09:52 EDT 2024. Contains 376008 sequences. (Running on oeis4.)