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 A027874 Minimal degree path length of a tree with n leaves. 1
 0, 4, 9, 16, 23, 30, 38, 46, 54, 64, 74, 84, 94, 104, 114, 124, 134, 144, 155, 166, 177, 188, 199, 210, 221, 232, 243, 256, 269, 282, 295, 308, 321, 334, 347, 360, 373, 386, 399, 412, 425, 438, 451, 464, 477, 490, 503, 516, 529, 542, 555, 568, 581, 594, 608 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES Theorem 5.4.9L in D. E. Knuth, `The Art of Computer Programming', Volume 3. LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 FORMULA a(n) = 3*q*n+2*(n-3^q), if 2*3^(q-1)<=n<=3^q; 3*q*n+4*(n-3^q), if 3^q<=n<=2*3^q. MAPLE a:= n-> (q-> `if`(n>2*3^q, 3*(q+1)*n+2*(n-3^(q+1)),          3*q*n+4*(n-3^q)))(ilog[3](n)): seq(a(n), n=1..60);  # Alois P. Heinz, Feb 22 2018 MATHEMATICA a[n_] := For[q = 0, True, q++, If[2*3^(q-1) <= n <= 3^q, Return[3*q*n + 2*(n-3^q)], If[3^q <= n <= 2*3^q, Return[3*q*n + 4*(n-3^q)]]]]; Array[a, 55] (* Jean-François Alcover, Oct 26 2015 *) CROSSREFS Cf. A003314. Sequence in context: A162207 A092614 A085899 * A009850 A009853 A008030 Adjacent sequences:  A027871 A027872 A027873 * A027875 A027876 A027877 KEYWORD nonn,easy,nice AUTHOR EXTENSIONS More terms from James A. Sellers STATUS approved

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Last modified March 19 00:55 EDT 2018. Contains 300772 sequences. (Running on oeis4.)