A373305
Sum over all complete compositions of n of the element set cardinality.
Original entry on oeis.org
0, 1, 1, 5, 7, 15, 41, 77, 161, 325, 727, 1460, 3058, 6228, 12815, 26447, 54099, 110800, 226247, 461531, 939678, 1914189, 3890279, 7905962, 16045367, 32550830, 65971827, 133645098, 270561031, 547468214, 1107208235, 2238242852, 4522679064, 9135128917
Offset: 0
a(1) = 1: 1.
a(2) = 1: 11.
a(3) = 5 = 2 + 2 + 1: 12, 21, 111.
a(4) = 7 = 2 + 2 + 2 + 1: 112, 121, 211, 1111.
a(5) = 15 = 7*2 + 1: 122, 212, 221, 1112, 1121, 1211, 2111, 11111.
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g:= proc(n, i, t) `if`(n=0, `if`(i=0, t!, 0),
`if`(i<1 or n add(g(n, k, 0)*k, k=0..floor((sqrt(1+8*n)-1)/2)):
seq(a(n), n=0..33);
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g[n_, i_, t_] := If[n == 0, If[i == 0, t!, 0], If[i < 1 || n < i*(i+1)/2, 0, b[n, i, t]]];
b[n_, i_, t_] := b[n, i, t] = Sum[g[n-i*j, i-1, t+j]/j!, {j, 1, n/i}];
a[n_] := Sum[g[n, k, 0]*k, {k, 0, Floor[(Sqrt[1 + 8*n] - 1)/2]}];
Table[a[n], {n, 0, 33}] (* Jean-François Alcover, Jun 08 2024, after Alois P. Heinz *)
A374727
Number of n-color complete compositions of n.
Original entry on oeis.org
1, 1, 1, 1, 7, 13, 45, 91, 233, 477, 1079, 2205, 4709, 10299, 22393, 52005, 125055, 310373, 799677, 2096699, 5556681, 14806685, 39417431, 104570549, 276027337, 724183555, 1887993925, 4891368373, 12595644523, 32252683453, 82146468813, 208225916203, 525472131209
Offset: 1
a(6) = 13 counts: (1,1,1,1,1,1) and the 12 permutations of parts 1, 1, 2_a, and 2_b.
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colr(x,y)={my(r=y-x+1, v=[x..y], z = vector(r*(r+(1+(x-1)*2))/2), k=1); for(i=1,#v,for(j=1,v[i],z[k]=v[i]; k++)); return(z)}
C_x(s,N)={my(x='x+O('x^N), g=if(#s <1,1, sum(i=1,#s, C_x(s[^i],N) * x^(s[i]) )/(1-sum(i=1,#s, x^(s[i]))))); return(g)}
B_x(N)={my(x='x+O('x^N), j=1, h=0, s=colr(1,j)); while(vecsum(s) <= N, h += C_x(s,N+1); j++;s=colr(1,j)); my(a = Vec(h)); vector(N, i, a[i])}
B_x(25)
A374728
Number of n-color gap-free compositions of n.
Original entry on oeis.org
1, 1, 1, 3, 7, 19, 45, 105, 239, 507, 1079, 2303, 4829, 10425, 23263, 53363, 127995, 318983, 816057, 2133241, 5640135, 14975051, 39772751, 105322879, 277547989, 727276225, 1894282195, 4903985955, 12621154315, 32302574959, 82248961437, 208426306113, 525884062427
Offset: 1
a(5) = 7 counts: (1,1,1,1,1), (1,2_a,2_b), (1,2_b,2_a), (2_a,1,2_b), (2_a,2_b,1), (2_b,1,2_a), (2_b,2_a,1).
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colr(x,y)={my(r=y-x+1, v=[x..y], z = vector(r*(r+(1+(x-1)*2))/2), k=1); for(i=1,#v,for(j=1,v[i],z[k]=v[i]; k++)); return(z)}
C_x(s,N)={my(x='x+O('x^N), g=if(#s <1,1, sum(i=1,#s, C_x(s[^i],N+1) * x^(s[i]) )/(1-sum(i=1,#s, x^(s[i]))))); return(g)}
B_x(N)={my(x='x+O('x^N), h=0); for(u=1,N, my(j=0); while(vecsum(colr(u,u+j)) <= N, h += C_x(colr(u,u+j),N+1); j++)); my(a = Vec(h)); vector(N, i, a[i])}
B_x(20)
A372702
Number of compositions of n such that the set of parts is {1,2,3}.
Original entry on oeis.org
6, 12, 32, 72, 152, 311, 625, 1225, 2378, 4566, 8700, 16475, 31052, 58290, 109079, 203584, 379144, 704821, 1308268, 2425259, 4491074, 8308879, 15360082, 28376089, 52391492, 96683649, 178344205, 328854566, 606190627, 1117103729, 2058129088, 3791056189
Offset: 6
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b:= proc(n, t) option remember; `if`(n=0, `if`(t=7, 1, 0),
add(b(n-j, Bits[Or](t, 2^(j-1))), j=1..min(n, 3)))
end:
a:= n-> b(n, 0):
seq(a(n), n=6..42); # Alois P. Heinz, May 25 2024
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C_x(s,N)={my(x='x+O('x^N), g=if(#s <1,1, sum(i=1,#s, C_x(setminus(s,[s[i]]),N) * x^(s[i]) )/(1-sum(i=1,#s, x^(s[i]))))); return(g)}
B_x(n) ={my(h=C_x([1,2,3],n)); Vec(h)}
B_x(40)
A380822
Triangle read by rows: T(n,k) is the number of compositions of n with k pairs of equal adjacent parts and all parts in standard order.
Original entry on oeis.org
1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 3, 1, 0, 1, 2, 1, 4, 1, 0, 1, 3, 3, 3, 5, 1, 0, 1, 2, 10, 5, 4, 6, 1, 0, 1, 5, 9, 17, 8, 5, 7, 1, 0, 1, 8, 16, 22, 26, 10, 6, 8, 1, 0, 1, 10, 35, 33, 37, 37, 12, 7, 9, 1, 0, 1, 19, 44, 80, 59, 56, 48, 14, 8, 10, 1, 0, 1
Offset: 1
Triangle begins:
k=0 1 2 3 4 5 6 7 8 9
n=1 [1],
n=2 [0, 1],
n=3 [1, 0, 1],
n=4 [1, 1, 0, 1],
n=5 [0, 3, 1, 0, 1],
n=6 [2, 1, 4, 1, 0, 1],
n=7 [3, 3, 3, 5, 1, 0, 1],
n=8 [2, 10, 5, 4, 6, 1, 0, 1],
n=9 [5, 9, 17, 8, 5, 7, 1, 0, 1],
n=10 [8, 16, 22, 26, 10, 6, 8, 1, 0, 1],
...
Row n = 6 counts:
T(6,0) = 2: (1,2,1,2), (1,2,3).
T(6,1) = 1: (1,2,2,1).
T(6,2) = 4: (1,1,1,2,1), (1,1,2,1,1), (1,1,2,2), (1,2,1,1,1).
T(6,3) = 1: (1,1,1,1,2).
T(6,4) = 0: .
T(6,5) = 1: (1,1,1,1,1,1).
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b:= proc(n, l, i) option remember; expand(`if`(n=0, 1, add(
`if`(j=l, x, 1)*b(n-j, j, max(i, j)), j=1..min(n, i+1))))
end:
T:= (n, k)-> coeff(b(n, 0$2), x, k):
seq(seq(T(n, k), k=0..n-1), n=1..12); # Alois P. Heinz, May 08 2025
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G(k,N) = {my(x='x+O('x^N)); if(k<1,1, G(k-1,N) * x^k * (1 + (1/(1 - sum(j=1,k, x^j/(1-(z-1)*x^j)))) * sum(j=1,k, z^(if(j==k,1,0)) * x^j/(1-(z-1)*x^j))))}
T_xz(max_row) = {my(N = max_row+1, x='x+O('x^N), h = sum(i=1,N/2+1, G(i,N))); vector(N-1, n, Vecrev(polcoeff(h, n)))}
T_xz(10)
A383713
Triangle read by rows: T(n,k) is the number of compositions of n with k parts all in standard order.
Original entry on oeis.org
1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 2, 1, 0, 0, 0, 1, 3, 1, 0, 0, 0, 1, 3, 4, 1, 0, 0, 0, 0, 4, 6, 5, 1, 0, 0, 0, 0, 2, 10, 10, 6, 1, 0, 0, 0, 0, 1, 9, 20, 15, 7, 1, 0, 0, 0, 0, 1, 7, 25, 35, 21, 8, 1, 0, 0, 0, 0, 0, 7, 26, 55, 56, 28, 9, 1, 0, 0, 0, 0, 0, 4, 29, 71, 105, 84, 36, 10, 1
Offset: 0
Triangle begins:
k=0 1 2 3 4 5 6 7 8 9 10
n=0 [1],
n=1 [0, 1],
n=2 [0, 0, 1],
n=3 [0, 0, 1, 1],
n=4 [0, 0, 0, 2, 1],
n=5 [0, 0, 0, 1, 3, 1],
n=6 [0, 0, 0, 1, 3, 4, 1],
n=7 [0, 0, 0, 0, 4, 6, 5, 1],
n=8 [0, 0, 0, 0, 2, 10, 10, 6, 1],
n=9 [0, 0, 0, 0, 1, 9, 20, 15, 7, 1],
n=10 [0, 0, 0, 0, 1, 7, 25, 35, 21, 8, 1],
...
Row n = 6 counts:
T(6,3) = 1: (1,2,3).
T(6,4) = 3: (1,1,2,2), (1,2,1,2), (1,2,2,1).
T(6,5) = 4: (1,1,1,1,2), (1,1,1,2,1), (1,1,2,1,1), (1,2,1,1,1).
T(6,6) = 1: (1,1,1,1,1,1).
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T_xy(max_row) = {my(N = max_row+1, x='x+O('x^N), h = 1 + sum(i=1,1+(N/2), y^i * x^(i*(i+1)/2)/prod(j=1,i, 1 - y*(x-x^(j+1))/(1-x)))); vector(N, n, Vecrev(polcoeff(h, n-1)))}
T_xy(10)
A330937
Number of strictly recursively normal integer partitions of n.
Original entry on oeis.org
1, 2, 3, 5, 7, 10, 15, 20, 27, 35, 49, 58, 81, 100, 126, 160, 206, 246, 316, 374, 462, 564, 696, 813, 1006, 1195, 1441, 1701, 2058, 2394, 2896, 3367, 4007, 4670, 5542, 6368, 7540, 8702, 10199, 11734, 13760, 15734, 18384, 21008, 24441, 27893, 32380, 36841
Offset: 0
The a(1) = 1 through a(9) = 15 partitions:
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(21) (31) (32) (42) (43) (53) (54)
(211) (41) (51) (52) (62) (63)
(221) (321) (61) (71) (72)
(311) (411) (322) (332) (81)
(331) (422) (432)
(421) (431) (441)
(511) (521) (522)
(3211) (611) (531)
(3221) (621)
(4211) (711)
(3321)
(4221)
(4311)
(5211)
(32211)
The narrow instead of strict version is
A332272.
A wide instead of strict version is
A332295(n) - 1 for n > 1.
Cf.
A107429,
A181819,
A316496,
A317081,
A317245,
A317491,
A329744,
A329746,
A329766,
A332277,
A332576.
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normQ[m_]:=m=={}||Union[m]==Range[Max[m]];
recnQ[ptn_]:=With[{qtn=Length/@Split[ptn]},Or[ptn=={},UnsameQ@@qtn,And[normQ[qtn],recnQ[qtn]]]];
Table[Length[Select[IntegerPartitions[n],recnQ]],{n,0,30}]
A356737
Number of integer partitions of n into odd parts covering an interval of odd numbers.
Original entry on oeis.org
1, 1, 1, 2, 2, 3, 3, 4, 4, 6, 6, 7, 8, 9, 10, 13, 13, 15, 17, 19, 21, 25, 26, 29, 33, 37, 40, 46, 49, 54, 61, 66, 72, 81, 87, 97, 106, 115, 125, 139, 150, 163, 179, 193, 210, 232, 248, 269, 293, 317, 343, 373, 401, 433, 470, 507, 545, 590, 633, 682, 737, 790
Offset: 0
The a(1) = 1 through a(9) = 6 partitions:
1 11 3 31 5 33 7 53 9
111 1111 311 3111 331 3311 333
11111 111111 31111 311111 531
1111111 11111111 33111
3111111
111111111
The initial case for compositions is
A356604.
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nogapQ[m_]:=Or[m=={},Union[m]==Range[Min[m],Max[m]]];
Table[Length[Select[IntegerPartitions[n],And@@OddQ/@#&&nogapQ[(#+1)/2]&]],{n,0,30}]
A373196
Maximal coefficient (in absolute value) in the numerator of C({1..n},x).
Original entry on oeis.org
1, 1, 2, 17, 444, 66559954, 14648786369948422, 791540878703169050660325841979096789557779, 1918013047695258943191946313451491492494186620117241479813740479213857275772347178176158
Offset: 0
C_x({1,2,3},x) = (-x^15 - 5*x^14 - 12*x^13 - 17*x^12 - 11*x^11 + 4*x^10 + 16*x^9 + 10*x^8 - 6*x^6)/(x^15 + 4*x^14 + 7*x^13 + 4*x^12 - 8*x^11 - 18*x^10 - 13*x^9 + 7*x^8 + 19*x^7 + 11*x^6 - 6*x^5 - 10*x^4 - 2*x^3 + 3*x^2 + 2*x - 1) with maximal coefficient abs(-17) in the numerator, so a(3) = 17.
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C_x(s)={my(g=if(#s <1,1, sum(i=1,#s, C_x(s[^i])*x^(s[i]))/(1-sum(i=1,#s, x^(s[i]))))); return(g)}
a(n)={vecmax(abs(Vec(numerator(C_x([1..n])))))}
A376117
Irregular triangle of numerator polynomial coefficients of C({1..n},x), T(n,k) for n >= 0 and k >= A000217(n).
Original entry on oeis.org
1, 1, -2, -1, -6, 0, 10, 16, 4, -11, -17, -12, -5, -1, -24, 84, -60, 30, -144, -48, 104, 186, 268, -12, -240, -436, -348, -46, 262, 444, 391, 199, -23, -166, -207, -172, -109, -55, -21, -6, -1, 120, -1200, 4560, -7740, 5064, -2472, 9768, -19152, 35004, -39408
Offset: 0
For row n = 2, C({1,2},x) = (-2*x^3 - x^4)/(1 + x + 2*x^2 - x^3 - x^4).
Triangle begins
k=0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
n=0 1;
n=1 . 1;
n=2 . . . -2, -1;
n=3 . . . . . . -6, 0, 10, 16, 4, -11, -17, -12, -5, -1;
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C_x(s)={my( g=if(#s <1, 1, sum(i=1, #s, C_x(s[^i]) * x^(s[i]) )/(1-sum(i=1, #s, x^(s[i]))))); return(g)}
A376117_row(n)={my(t=n*(n+1)/2, c=C_x([1..n]), d=poldegree(numerator(c))-t, z=vector(d+1)); for(k=0,d,z[k+1]=polcoeff(numerator(c),k+t)); z}
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