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 A183906 Number of nondecreasing arrangements of n+2 numbers in 0..3 with each number being the sum mod 4 of two others. 1
 2, 5, 17, 38, 67, 105, 153, 212, 283, 367, 465, 578, 707, 853, 1017, 1200, 1403, 1627, 1873, 2142, 2435, 2753, 3097, 3468, 3867, 4295, 4753, 5242, 5763, 6317, 6905, 7528, 8187, 8883, 9617, 10390, 11203, 12057, 12953, 13892, 14875, 15903, 16977, 18098 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A183912. LINKS R. H. Hardin, Table of n, a(n) for n = 1..199 FORMULA Empirical: a(n) = (1/6)*n^3 + 2*n^2 + (5/6)*n - 8 for n>2. Conjectures from Colin Barker, Apr 05 2018: (Start) G.f.: x*(2 - 3*x + 9*x^2 - 8*x^3 - x^4 + 2*x^5) / (1 - x)^4. a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>6. (End) EXAMPLE All solutions for n=2: ..1....0....0....0....1 ..1....0....0....2....2 ..2....0....2....2....3 ..3....0....2....2....3 CROSSREFS Cf. A183912. Sequence in context: A127436 A064168 A118727 * A042361 A114300 A099207 Adjacent sequences:  A183903 A183904 A183905 * A183907 A183908 A183909 KEYWORD nonn AUTHOR R. H. Hardin, Jan 07 2011 STATUS approved

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Last modified December 11 21:28 EST 2018. Contains 318052 sequences. (Running on oeis4.)