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 A048808 Number of rooted trees with n nodes with every leaf at height 3. 11
 1, 1, 2, 3, 5, 7, 12, 18, 27, 42, 64, 96, 146, 219, 327, 491, 730, 1084, 1608, 2376, 3500, 5154, 7563, 11076, 16193, 23625, 34395, 50005, 72550, 105089, 151984, 219448, 316362, 455434, 654661, 939736, 1347137, 1928593, 2757449, 3937675 (list; graph; refs; listen; history; text; internal format)
 OFFSET 4,3 LINKS Vaclav Kotesovec, Table of n, a(n) for n = 4..10000 (terms 4..1000 from Alois P. Heinz) N. J. A. Sloane, Transforms FORMULA Euler transform of A002865 (with a(0)=0) shifted right. MATHEMATICA T[n_, k_] := T[n, k] = If[n == 1, 1, If[k == 0, 0, Sum[Sum[If[d < k, 0, T[d, k - 1]*d], {d, Divisors[j]}]*T[n - j, k], {j, 1, n - 1}]/(n - 1)]]; a[n_] := T[n, 3]; Table[a[n], {n, 4, 50}] (* Jean-François Alcover, May 11 2019, after Alois P. Heinz in A244925 *) CROSSREFS Cf. A048809-A048816. Column k=3 of A244925. Sequence in context: A206290 A091696 A280303 * A263358 A239915 A013983 Adjacent sequences:  A048805 A048806 A048807 * A048809 A048810 A048811 KEYWORD nonn AUTHOR Christian G. Bower, Apr 15 1999 STATUS approved

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Last modified January 18 19:43 EST 2020. Contains 331029 sequences. (Running on oeis4.)