A032305
Number of rooted trees where any 2 subtrees extending from the same node have a different number of nodes.
Original entry on oeis.org
1, 1, 1, 2, 3, 6, 12, 25, 51, 111, 240, 533, 1181, 2671, 6014, 13795, 31480, 72905, 168361, 393077, 914784, 2150810, 5040953, 11914240, 28089793, 66702160, 158013093, 376777192, 896262811, 2144279852, 5120176632, 12286984432, 29428496034, 70815501209
Offset: 1
The a(6) = 6 fully unbalanced trees: (((((o))))), (((o(o)))), ((o((o)))), (o(((o)))), (o(o(o))), ((o)((o))). - _Gus Wiseman_, Jan 10 2018
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A:= proc(n) if n<=1 then x else convert(series(x* (product(1+ coeff(A(n-1), x,i)*x^i, i=1..n-1)), x=0, n+1), polynom) fi end: a:= n-> coeff(A(n), x,n): seq(a(n), n=1..31); # Alois P. Heinz, Aug 22 2008
# second Maple program:
g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(`if`(j=0, 1, g((i-1)$2))*g(n-i*j, i-1), j=0..min(1, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=1..35); # Alois P. Heinz, Mar 04 2013
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nn=30;f[x_]:=Sum[a[n]x^n,{n,0,nn}];sol=SolveAlways[0 == Series[f[x]-x Product[1+a[i]x^i,{i,1,nn}],{x,0,nn}],x];Table[a[n],{n,1,nn}]/.sol (* Geoffrey Critzer, Nov 17 2012 *)
allnim[n_]:=If[n===1,{{}},Join@@Function[c,Select[Union[Sort/@Tuples[allnim/@c]],UnsameQ@@(Count[#,_List,{0,Infinity}]&/@#)&]]/@IntegerPartitions[n-1]];
Table[Length[allnim[n]],{n,15}] (* Gus Wiseman, Jan 10 2018 *)
g[n_, i_] := g[n, i] = If[n == 0, 1, If[i < 1, 0,
Sum[If[j == 0, 1, g[i-1, i-1]]*g[n-i*j, i-1], {j, 0, Min[1, n/i]}]]];
a[n_] := g[n-1, n-1];
Array[a, 35] (* Jean-François Alcover, May 21 2021, after Alois P. Heinz *)
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a(n)=polcoeff(x*prod(i=1,n-1,1+a(i)*x^i)+x*O(x^n),n)
A318754
Number T(n,k) of rooted trees with n nodes such that k equals the maximal number of subtrees extending from the same node and having the same number of nodes; 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, 2, 1, 1, 0, 3, 4, 1, 1, 0, 6, 9, 3, 1, 1, 0, 12, 22, 9, 3, 1, 1, 0, 25, 54, 23, 8, 3, 1, 1, 0, 51, 139, 60, 23, 8, 3, 1, 1, 0, 111, 346, 166, 61, 22, 8, 3, 1, 1, 0, 240, 892, 447, 167, 61, 22, 8, 3, 1, 1, 0, 533, 2290, 1219, 461, 168, 60, 22, 8, 3, 1, 1
Offset: 1
Triangle T(n,k) begins:
1;
0, 1;
0, 1, 1;
0, 2, 1, 1;
0, 3, 4, 1, 1;
0, 6, 9, 3, 1, 1;
0, 12, 22, 9, 3, 1, 1;
0, 25, 54, 23, 8, 3, 1, 1;
0, 51, 139, 60, 23, 8, 3, 1, 1;
0, 111, 346, 166, 61, 22, 8, 3, 1, 1;
Columns k=0-10 give:
A063524,
A032305 (for n>1),
A318817,
A318818,
A318819,
A318820,
A318821,
A318822,
A318823,
A318824,
A318825.
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g:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g(i-1$2, k)+j-1, j)*g(n-i*j, i-1, k), j=0..min(k, n/i))))
end:
T:= (n, k)-> g(n-1$2, k) -`if`(k=0, 0, g(n-1$2, k-1)):
seq(seq(T(n, k), k=0..n-1), n=1..14);
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g[n_, i_, k_] := g[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[Binomial[g[i - 1, i - 1, k] + j - 1, j]*g[n - i*j, i - 1, k], {j, 0, Min[k, n/i]}]]];
T[n_, k_] := g[n - 1, n - 1, k] - If[k == 0, 0, g[n - 1, n - 1, k - 1]];
Table[T[n, k], {n, 1, 14}, {k, 0, n - 1}] // Flatten (* Jean-François Alcover, May 27 2019, after Alois P. Heinz *)
A318757
Number A(n,k) of rooted trees with n nodes such that no more than k isomorphic subtrees extend from the same node; square array A(n,k), n>=0, k>=0, read by antidiagonals.
Original entry on oeis.org
0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 3, 3, 0, 0, 1, 1, 2, 4, 7, 6, 0, 0, 1, 1, 2, 4, 8, 15, 12, 0, 0, 1, 1, 2, 4, 9, 18, 34, 25, 0, 0, 1, 1, 2, 4, 9, 19, 43, 79, 52, 0, 0, 1, 1, 2, 4, 9, 20, 46, 102, 190, 113, 0, 0, 1, 1, 2, 4, 9, 20, 47, 110, 250, 459, 247, 0
Offset: 0
Square array A(n,k) begins:
0, 0, 0, 0, 0, 0, 0, 0, 0, ...
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
0, 1, 1, 1, 1, 1, 1, 1, 1, ...
0, 1, 2, 2, 2, 2, 2, 2, 2, ...
0, 2, 3, 4, 4, 4, 4, 4, 4, ...
0, 3, 7, 8, 9, 9, 9, 9, 9, ...
0, 6, 15, 18, 19, 20, 20, 20, 20, ...
0, 12, 34, 43, 46, 47, 48, 48, 48, ...
0, 25, 79, 102, 110, 113, 114, 115, 115, ...
Columns k=0-10 give:
A063524,
A004111,
A248869,
A318850,
A318851,
A318852,
A318853,
A318854,
A318855,
A318856,
A318857.
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h:= proc(n, m, t, k) option remember; `if`(m=0, binomial(n+t, t),
`if`(n=0, 0, add(h(n-1, m-j, t+1, k), j=1..min(k, m))))
end:
b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(b(n-i*j, i-1, k)*h(A(i, k), j, 0, k), j=0..n/i)))
end:
A:= (n, k)-> `if`(n<2, n, b(n-1$2, k)):
seq(seq(A(n, d-n), n=0..d), d=0..14);
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h[n_, m_, t_, k_] := h[n, m, t, k] = If[m == 0, Binomial[n + t, t], If[n == 0, 0, Sum[h[n - 1, m - j, t + 1, k], {j, 1, Min[k, m]}]]];
b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[b[n - i*j, i - 1, k]*h[A[i, k], j, 0, k], {j, 0, n/i}]]];
A[n_, k_] := If[n < 2, n, b[n - 1, n - 1, k]];
Table[A[n, d - n], {d, 0, 14}, {n, 0, d}] // Flatten (* Jean-François Alcover, May 11 2019, after Alois P. Heinz *)
A213920
Number of rooted trees with n nodes such that no more than two subtrees corresponding to children of any node have the same number of nodes.
Original entry on oeis.org
0, 1, 1, 2, 3, 7, 15, 34, 79, 190, 457, 1132, 2823, 7126, 18136, 46541, 120103, 312109, 815012, 2137755, 5632399, 14895684, 39519502, 105198371, 280815067, 751490363, 2016142768, 5420945437, 14604580683, 39425557103, 106618273626, 288792927325, 783516425820
Offset: 0
: o : o : o o : o o o :
: : | : / \ | : | / \ | :
: : o : o o o : o o o o :
: : : | : / \ | | :
: : : o : o o o o :
: : : : | :
: n=1 : n=2 : n=3 : n=4 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 :
: | :
: n=5 o :
:.........................................:
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(2, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
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g[n_, i_] := g[n, i] = If[n==0, 1, If[i<1, 0, Sum[Binomial[g[i-1, i-1]+j-1, j]*g[n-i*j, i-1], {j, 0, Min[2, n/i]}]]]; a[n_] := g[n-1, n-1]; Table[ a[n], {n, 0, 40}] (* Jean-François Alcover, Feb 21 2017, translated from Maple *)
A318804
Number of rooted trees with n nodes such that no more than ten subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 20, 48, 115, 286, 719, 1842, 4765, 12484, 32968, 87798, 235346, 634752, 1720897, 4687949, 12824195, 35216118, 97039045, 268237121, 743594937, 2066803841, 5758576675, 16080698759, 44998355630, 126161517745, 354354779794, 996963790045, 2809334906744, 7928088014833, 22404525682610
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(10, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
A318797
Number of rooted trees with n nodes such that no more than three subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 8, 18, 43, 102, 250, 623, 1579, 4042, 10470, 27350, 72034, 190956, 509259, 1365271, 3677522, 9947145, 27007988, 73582758, 201103314, 551190098, 1514683667, 4172470962, 11519509386, 31869341642, 88337853393, 245301368188, 682307613945
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(3, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
A318798
Number of rooted trees with n nodes such that no more than four subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 19, 46, 110, 273, 684, 1746, 4503, 11758, 30943, 82118, 219337, 589477, 1592427, 4322386, 11781435, 32235285, 88502260, 243747792, 673238061, 1864400173, 5175591107, 14399672901, 40146278964, 112143682477, 313822403439, 879673332422
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(4, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
A318799
Number of rooted trees with n nodes such that no more than five subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 20, 47, 113, 281, 706, 1807, 4671, 12223, 32245, 85777, 229670, 618732, 1675523, 4558995, 12456746, 34166520, 94034681, 259621349, 718846409, 1995609079, 5553497132, 15489246752, 43290735944, 121226413303, 340079037154, 955633681302
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(5, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
A318800
Number of rooted trees with n nodes such that no more than six subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 20, 48, 114, 284, 714, 1829, 4731, 12391, 32711, 87083, 233347, 629132, 1705026, 4642964, 12696279, 34851400, 95996667, 265251800, 735029359, 2042187008, 5687725928, 15876511087, 44409195451, 124459715968, 349434210318, 982723567822
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(6, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
A318801
Number of rooted trees with n nodes such that no more than seven subtrees of the same size extend from the same node.
Original entry on oeis.org
0, 1, 1, 2, 4, 9, 20, 48, 115, 285, 717, 1837, 4753, 12451, 32878, 87549, 234654, 632813, 1715444, 4672539, 12780498, 35091807, 96684475, 267223388, 740690724, 2058468449, 5734614700, 16011714519, 44799497408, 125587597723, 352696619768, 992168346445
Offset: 0
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g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(7, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
Showing 1-10 of 12 results.
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