A244454
Number T(n,k) of unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals k; triangle T(n,k), n>=1, 0<=k<=n-1, read by rows.
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 3, 0, 1, 0, 7, 1, 0, 1, 0, 17, 2, 0, 0, 1, 0, 42, 4, 1, 0, 0, 1, 0, 105, 7, 2, 0, 0, 0, 1, 0, 267, 15, 2, 1, 0, 0, 0, 1, 0, 684, 28, 4, 2, 0, 0, 0, 0, 1, 0, 1775, 56, 7, 2, 1, 0, 0, 0, 0, 1, 0, 4639, 110, 12, 2, 2, 0, 0, 0, 0, 0, 1
Offset: 1
The A000081(5) = 9 rooted trees with 5 nodes sorted by minimal outdegree of inner nodes are:
: o o o o o o o : o : o :
: | | | / \ / \ | /|\ : / \ : /( )\ :
: o o o o o o o o o o o : o o : o o o o :
: | | / \ | | | /|\ | : / \ : :
: o o o o o o o o o o o : o o : :
: | / \ | | : : :
: o o o o o : : :
: | : : :
: o : : :
: : : :
: ------------------1------------------ : ---2--- : ---4--- :
Thus row 5 = [0, 7, 1, 0, 1].
Triangle T(n,k) begins:
1;
0, 1;
0, 1, 1;
0, 3, 0, 1;
0, 7, 1, 0, 1;
0, 17, 2, 0, 0, 1;
0, 42, 4, 1, 0, 0, 1;
0, 105, 7, 2, 0, 0, 0, 1;
0, 267, 15, 2, 1, 0, 0, 0, 1;
0, 684, 28, 4, 2, 0, 0, 0, 0, 1;
0, 1775, 56, 7, 2, 1, 0, 0, 0, 0, 1;
0, 4639, 110, 12, 2, 2, 0, 0, 0, 0, 0, 1;
Columns k=0-10 give:
A063524,
A244455,
A244456,
A244457,
A244458,
A244459,
A244460,
A244461,
A244462,
A244463,
A244464.
-
b:= proc(n, i, t, k) option remember; `if`(n=0, `if`(t in [0, k],
1, 0), `if`(i<1, 0, add(binomial(b((i-1)$2, k$2)+j-1, j)*
b(n-i*j, i-1, max(0, t-j), k), j=0..n/i)))
end:
T:= (n, k)-> b(n-1$2, k$2) -`if`(n=1 and k=0, 0, b(n-1$2, k+1$2)):
seq(seq(T(n, k), k=0..n-1), n=1..14);
-
b[n_, i_, t_, k_] := b[n, i, t, k] = If[n == 0, If[t == 0 || t == k, 1, 0], If[i<1, 0, Sum[Binomial[b[i-1, i-1, k, k]+j-1, j]* b[n-i*j, i-1, Max[0, t-j], k], {j, 0, n/i}]]]; T[n_, k_] := b[n-1, n-1, k, k] - If[n == 1 && k == 0, 0, b[n-1, n-1, k+1, k+1]]; Table[Table[T[n, k], {k, 0, n-1}], {n, 1, 14}] // Flatten (* Jean-François Alcover, Jan 08 2015, translated from Maple *)
A244531
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 2.
Original entry on oeis.org
1, 0, 2, 5, 11, 28, 78, 201, 532, 1441, 3895, 10569, 28926, 79493, 219226, 607189, 1687880, 4706737, 13165215, 36929595, 103860429, 292808814, 827392709, 2342964435, 6647953886, 18898472568, 53818654942, 153518738980, 438602656951, 1254943919799, 3595714927194
Offset: 3
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 2$2) -b(n-1, 3$2):
seq(a(n), n=3..50);
-
b[n_, t_, k_] := b[n, t, k] = If[n == 0, If[t == 0 || t == k, 1, 0], If[t > n, 0, Sum[b[j - 1, k, k]*b[n - j, Max[0, t - 1], k], {j, 1, n}]]]; T[n_, k_] := b[n - 1, k, k] - If[n == 1 && k == 0, 0, b[n - 1, k + 1, k + 1]]; a[n_] := b[n - 1, 2, 2] - b[n - 1, 3, 3]; Table[a[n], {n, 3, 50}] (* Jean-François Alcover, Feb 06 2015, after Maple *)
A244532
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 3.
Original entry on oeis.org
1, 0, 0, 3, 7, 8, 21, 55, 121, 265, 611, 1379, 3193, 7436, 17085, 39339, 91846, 214549, 500132, 1169267, 2743302, 6445797, 15167805, 35749961, 84390645, 199523566, 472429633, 1120012481, 2658525869, 6318368820, 15034189965, 35811690663, 85393261630
Offset: 4
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 3$2) -b(n-1, 4$2):
seq(a(n), n=4..40);
-
b[n_, t_, k_] := b[n, t, k] = If[n == 0, If[t == 0 || t == k, 1, 0], If[t > n, 0, Sum[b[j - 1, k, k]*b[n - j, Max[0, t - 1], k], {j, 1, n}]]]; T[n_, k_] := b[n - 1, k, k] - If[n == 1 && k == 0, 0, b[n - 1, k + 1, k + 1]]; a[n_] := b[n - 1, 3, 3] - b[n - 1, 4, 4]; Table[a[n], {n, 4, 40}] (* Jean-François Alcover, Feb 06 2015, after Maple *)
A244533
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 4.
Original entry on oeis.org
1, 0, 0, 0, 4, 9, 10, 11, 34, 91, 196, 330, 636, 1377, 2976, 6061, 12199, 25186, 52767, 109066, 224964, 467605, 979056, 2042847, 4244986, 8844130, 18527956, 38878929, 81460220, 170576593, 357894472, 752544917, 1583579674, 3332453026, 7016669752, 14790212086
Offset: 5
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 4$2) -b(n-1, 5$2):
seq(a(n), n=5..45);
-
b[n_, t_, k_] := b[n, t, k] = If[n == 0, If[t == 0 || t == k, 1, 0], If[t > n, 0, Sum[b[j - 1, k, k]*b[n - j, Max[0, t - 1], k], {j, 1, n}]]]; T[n_, k_] := b[n - 1, k, k] - If[n == 1 && k == 0, 0, b[n - 1, k + 1, k + 1]]; a[n_] := b[n - 1, 4, 4] - b[n - 1, 5, 5]; Table[a[n], {n, 5, 45}] (* Jean-François Alcover, Feb 06 2015, after Maple *)
A244534
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 5.
Original entry on oeis.org
1, 0, 0, 0, 0, 5, 11, 12, 13, 14, 50, 136, 289, 477, 703, 1255, 2611, 5489, 10902, 19712, 35455, 66651, 130014, 254737, 488041, 920461, 1741642, 3338360, 6453073, 12425997, 23780944, 45451155, 87224392, 168253246, 324863578, 625728091, 1202953325, 2314485753
Offset: 6
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 5$2) -b(n-1, 6$2):
seq(a(n), n=6..50);
-
b[n_, t_, k_] := b[n, t, k] = If[n == 0,
If[MemberQ[{0, k}, t], 1, 0], If[t > n, 0, Sum[b[j-1, k, k]*
b[n-j, Max[0, t-1], k], {j, n}]]];
a[n_] := b[n-1, 5, 5] - b[n-1, 6, 6];
Table[a[n], {n, 6, 50}] (* Jean-François Alcover, Aug 28 2021, after Maple code *)
A244535
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 6.
Original entry on oeis.org
1, 0, 0, 0, 0, 0, 6, 13, 14, 15, 16, 17, 69, 190, 400, 651, 946, 1288, 2186, 4425, 9126, 17811, 31654, 51997, 85841, 149916, 276056, 518089, 960466, 1718395, 3006963, 5269873, 9392821, 17032418, 31098198, 56432687, 101350402, 180978701, 323731177, 582832779
Offset: 7
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 6$2) -b(n-1, 7$2):
seq(a(n), n=7..50);
A244536
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 7.
Original entry on oeis.org
1, 0, 0, 0, 0, 0, 0, 7, 15, 16, 17, 18, 19, 20, 91, 253, 529, 852, 1225, 1651, 2133, 3493, 6931, 14095, 27156, 47648, 77297, 118031, 182462, 300441, 527398, 954712, 1722370, 3015910, 5074611, 8342271, 13730760, 23036563, 39558564, 68974240, 120541276
Offset: 8
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 7$2) -b(n-1, 8$2):
seq(a(n), n=8..50);
A244537
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 8.
Original entry on oeis.org
1, 0, 0, 0, 0, 0, 0, 0, 8, 17, 18, 19, 20, 21, 22, 23, 116, 325, 676, 1080, 1540, 2059, 2640, 3286, 5240, 10241, 20604, 39305, 68286, 109705, 165946, 239629, 351898, 552311, 931070, 1633871, 2879668, 4951860, 8208631, 13094200, 20436400, 31939817, 50935060
Offset: 9
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 8$2) -b(n-1, 9$2):
seq(a(n), n=9..55);
A244538
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 9.
Original entry on oeis.org
1, 0, 0, 0, 0, 0, 0, 0, 0, 9, 19, 20, 21, 22, 23, 24, 25, 26, 144, 406, 841, 1335, 1891, 2512, 3201, 3961, 4795, 7491, 14467, 28861, 54626, 94160, 150101, 225337, 323016, 446556, 629454, 949486, 1545877, 2639756, 4558225, 7716325, 12629776, 19928727, 30372551
Offset: 10
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 9$2) -b(n-1, 10$2):
seq(a(n), n=10..60);
A244539
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 10.
Original entry on oeis.org
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 21, 22, 23, 24, 25, 26, 27, 28, 29, 175, 496, 1024, 1617, 2278, 3010, 3816, 4699, 5662, 6708, 10310, 19721, 39074, 73487, 125862, 199365, 297436, 423799, 582472, 777777, 1060410, 1547051, 2443649, 4072732, 6905106, 11528110
Offset: 11
-
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 10$2) -b(n-1, 11$2):
seq(a(n), n=11..60);
Showing 1-10 of 10 results.
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