A238640
Position of [n, n, ..., n] (n n's) in Mathematica-ordered list of partitions of n^2.
Original entry on oeis.org
1, 1, 3, 19, 168, 1582, 15546, 157051, 1625368, 17159223, 184277224, 2008388660, 22172275440, 247558926150, 2791793968821, 31764451979736, 364283594455091, 4207485803818522, 48908343969469479, 571811846280602486, 6720473048598172508, 79363083519870386700
Offset: 0
The partitions of 4 in Mathematica order are 4, 31, 22, 211, 1111. The position of 22 is a(2) = 3.
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b:= proc(n, i) option remember; `if`(n=0, 1,
`if`(i<1, 0, b(n, i-1) +`if`(i>n, 0, b(n-i, i))))
end:
a:= n-> 1 +add(b(n^2-j, j), j=n+1..n^2):
seq(a(n), n=0..20); # Alois P. Heinz, Sep 03 2014
-
r[n_] := Table[n, {k, 1, n}]; Flatten[Table[Position[IntegerPartitions[n^2], r[n]], {n, 0, 8}]]
b[n_, i_] := b[n, i] = If[n==0, 1, If[i<1, 0, b[n, i-1]+If[i>n, 0, b[n-i, i]]]]; a[n_] := 1+Sum[b[n^2-j, j], {j, n+1, n^2}]; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Oct 28 2015, after Alois P. Heinz *)
A332706
Index position of {2}^n within the list of partitions of 2n in canonical ordering.
Original entry on oeis.org
1, 1, 3, 8, 18, 37, 71, 128, 223, 376, 617, 991, 1563, 2423, 3704, 5589, 8333, 12293, 17959, 25996, 37318, 53153, 75153, 105535, 147249, 204201, 281563, 386128, 526795, 715191, 966437, 1300125, 1741598, 2323487, 3087701, 4087933, 5392747, 7089463, 9289053
Offset: 0
a(3) = 8, because 222 has position 8 within the list of partitions of 6 in canonical ordering: 6, 51, 42, 411, 33, 321, 3111, 222, ... .
-
a:= n-> combinat[numbpart](2*n)-n:
seq(a(n), n=0..44);
-
a[n_] := PartitionsP[2n] - n;
Table[a[n], {n, 0, 44}] (* Jean-François Alcover, Aug 20 2021, from Maple *)
A238639
Position of [n, n-1, ..., 2, 1] in Mathematica-ordered list of partitions of n(n+1)/2.
Original entry on oeis.org
1, 1, 2, 6, 23, 103, 498, 2493, 12741, 66224, 348963, 1859009, 9994196, 54155387, 295477841, 1621962199, 8951635343, 49644856801, 276540258555, 1546630084062, 8681889729354, 48900895532763, 276302483274825, 1565747892473958, 8896975706929141, 50683901455201860
Offset: 0
The partitions of 6 in Mathematica order are 6, 51, 42, 411, 33, 321, 3111, 222, 2211, 21111, 111111. The position of 321 is a(3) = 6.
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g:= (n, i)-> `if`(n=0, 1, g(n-i+1, i-1)+ b(n-i, i)):
b:= proc(n, i) option remember; `if`(n=0, 1,
`if`(i<1, 0, b(n, i-1)+`if`(i>n, 0, b(n-i, i))))
end:
a:= n-> (m-> add(b(m-j, min(j, m-j)), j=n+1..m)+
g(m-n, n))(n*(n+1)/2):
seq(a(n), n=0..25); # Alois P. Heinz, Jun 03 2015
-
r[n_] := Table[n - k, {k, 0, n - 1}]; Flatten[Table[Position[IntegerPartitions[n (n + 1)/2], r[n]], {n, 0, 2}]]
g[n_, i_] := If[n==0, 1, g[n-i+1, i-1] + b[n-i, i]]; b[n_, i_] := b[n, i] = If[n==0, 1, If[i<1, 0, b[n, i-1] + If[i>n, 0, b[n-i, i]]]]; a[n_] := Function[m, Sum[b[m-j, Min[j, m-j]], {j, n+1, m}] + g[m-n, n]][n(n+1)/2]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Oct 28 2015, after Alois P. Heinz *)
A216053
a(n) is the position of the last two-tuple within the reverse lexicographic set of partitions of 2n and 2n+1, with a(1)-a(n) representing the positions of every 2-tuple partition of 2n and 2n+1.
Original entry on oeis.org
2, 3, 5, 8, 13, 20, 31, 46, 68, 98, 140, 196, 273, 374, 509, 685, 916, 1213, 1598, 2088, 2715, 3507, 4509, 5764, 7339, 9297, 11733, 14743, 18461, 23026, 28630, 35472, 43821, 53964, 66274, 81157, 99134, 120771, 146786, 177971, 215309, 259892, 313066, 376327
Offset: 1
With n = 3, 2n = 6. The partitions of 6 are {{6}, {5,1}, {4,2}, {4,1,1}, {3,3}, {3,2,1}, {3,1,1,1}, {2,2,2}, {2,2,1,1}, {2,1,1,1,1}, {1,1,1,1,1,1}}. The last 2-tuple is located at position 5. The positions of all 2-tuples are 2, 3, and 5.
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RecurrenceTable[{a[n+1] == a[n] + PartitionsP[(n)], a[1] == 2}, a, {n, 1, 44}]
A332719
Index position of {n}^3 within the list of partitions of 3n in canonical ordering.
Original entry on oeis.org
1, 3, 8, 19, 44, 93, 187, 357, 657, 1166, 2015, 3393, 5594, 9044, 14378, 22501, 34734, 52931, 79735, 118823, 175337, 256347, 371606, 534377, 762721, 1080979, 1521925, 2129330, 2961580, 4096006, 5634855, 7712558, 10505457, 14243772, 19227383, 25845241, 34600673
Offset: 0
a(2) = 8, because 222 has position 8 within the list of partitions of 6 in canonical ordering: 6, 51, 42, 411, 33, 321, 3111, 222, ... .
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b:= proc(n, i) option remember;
`if`(n=0, 1, b(n-i, i)+g(n, i-1))
end:
g:= proc(n, i) option remember; `if`(n=0 or i=1, 1,
`if`(i<1, 0, g(n-i, min(n-i, i))+g(n, i-1)))
end:
a:= n-> g(3*n$2)-b(3*n, n)+1:
seq(a(n), n=0..37);
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b[n_, i_] := b[n, i] = If[n == 0, 1, b[n - i, i] + g[n, i - 1]];
g[n_, i_] := g[n, i] = If[n == 0 || i == 1, 1, If[i < 1, 0, g[n - i, Min[n - i, i]] + g[n, i - 1]]];
a[n_] := g[3n, 3n] - b[3n, n] + 1;
a /@ Range[0, 37] (* Jean-François Alcover, Jan 06 2021, after Alois P. Heinz *)
A332720
Index position of {3}^n within the list of partitions of 3n in canonical ordering.
Original entry on oeis.org
1, 1, 5, 19, 59, 150, 349, 745, 1515, 2936, 5514, 10036, 17851, 31039, 53006, 88943, 147057, 239701, 385885, 613855, 966137, 1505137, 2323124, 3553914, 5392315, 8117758, 12131618, 18003740, 26543030, 38886999, 56633453, 82009410, 118113488, 169229009, 241264461
Offset: 0
a(2) = 5, because 33 has position 5 within the list of partitions of 6 in canonical ordering: 6, 51, 42, 411, 33, 321, 3111, 222, ... .
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b:= proc(n) option remember;
`if`(n=0, 1, b(n-1)+g(3*n, 2))
end:
g:= proc(n, i) option remember; `if`(n=0 or i=1, 1,
`if`(i<1, 0, g(n-i, min(n-i, i))+g(n, i-1)))
end:
a:= n-> g(3*n$2)-b(n)+1:
seq(a(n), n=0..35);
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b[n_] := b[n] = If[n == 0, 1, b[n - 1] + g[3n, 2]];
g[n_, i_] := g[n, i] = If[n == 0 || i == 1, 1, If[i < 1, 0, g[n - i, Min[n - i, i]] + g[n, i - 1]]];
a[n_] := g[3n, 3n] - b[n] + 1;
a /@ Range[0, 35] (* Jean-François Alcover, Jan 06 2021, after Alois P. Heinz *)
A330693
Regular subtriangle of A328773: T(n,k) is the number of the balanced colored digraphs on n nodes with k colors, 1 <= k <= n.
Original entry on oeis.org
1, 3, 4, 16, 36, 64, 218, 1104, 2112, 4096, 9608, 90416, 266496, 528384, 1048576, 1540944, 30194176, 135032832, 269500416, 537919488, 1073741824
Offset: 1
The balanced color scheme [2,2,2] has with A330661 the index 5 in A328773. So there are T(6,3) = A328773(6,5) = 135032832 digraphs with 6 nodes two each in the same color.
Triangle T(n,k) begins:
1;
3, 4;
16, 36, 64;
218, 1104, 2112, 4096;
9608, 90416, 266496, 528384, 1048576;
1540944, 30194176, 135032832, 269500416, 537919488, 1073741824;
...
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\\ here C(p) computes sequence value for given partition.
permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}
edges(v) = {sum(i=2, #v, sum(j=1, i-1, 2*gcd(v[i], v[j]))) + sum(i=1, #v, v[i]-1)}
C(p)={((i, v)->if(i>#p, 2^edges(v), my(s=0); forpart(q=p[i], s+=permcount(q)*self()(i+1, concat(v, Vec(q)))); s/p[i]!))(1, [])}
Row(n)={apply(C, vecsort([Vecrev(p) | p<-partitions(n),p[#p]-p[1]<=1], , 4))}
{ for(n=1, 6, print(Row(n))) }
Showing 1-7 of 7 results.
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