A358830
Number of twice-partitions of n into partitions with all different lengths.
Original entry on oeis.org
1, 1, 2, 4, 9, 15, 31, 53, 105, 178, 330, 555, 1024, 1693, 2991, 5014, 8651, 14242, 24477, 39864, 67078, 109499, 181311, 292764, 483775, 774414, 1260016, 2016427, 3254327, 5162407, 8285796, 13074804, 20812682, 32733603, 51717463, 80904644, 127305773, 198134675, 309677802
Offset: 0
The a(1) = 1 through a(5) = 15 twice-partitions:
(1) (2) (3) (4) (5)
(11) (21) (22) (32)
(111) (31) (41)
(11)(1) (211) (221)
(1111) (311)
(11)(2) (2111)
(2)(11) (11111)
(21)(1) (21)(2)
(111)(1) (22)(1)
(3)(11)
(31)(1)
(111)(2)
(211)(1)
(111)(11)
(1111)(1)
The version for set partitions is
A007837.
For sums instead of lengths we have
A271619.
For constant instead of distinct lengths we have
A306319.
The case of distinct sums also is
A358832.
The version for multiset partitions of integer partitions is
A358836.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],UnsameQ@@Length/@#&]],{n,0,10}]
-
seq(n)={ local(Cache=Map());
my(g=Vec(-1+1/prod(k=1, n, 1 - y*x^k + O(x*x^n))));
my(F(m,r,b) = my(key=[m,r,b], z); if(!mapisdefined(Cache,key,&z),
z = if(r<=0||m==0, r==0, self()(m-1, r, b) + sum(k=1, m, my(c=polcoef(g[m],k)); if(!bittest(b,k)&&c, c*self()(min(m,r-m), r-m, bitor(b, 1<Andrew Howroyd, Dec 31 2022
A358831
Number of twice-partitions of n into partitions with weakly decreasing lengths.
Original entry on oeis.org
1, 1, 3, 6, 14, 26, 56, 102, 205, 372, 708, 1260, 2345, 4100, 7388, 12819, 22603, 38658, 67108, 113465, 193876, 324980, 547640, 909044, 1516609, 2495023, 4118211, 6726997, 11002924, 17836022, 28948687, 46604803, 75074397, 120134298, 192188760, 305709858, 486140940
Offset: 0
The a(1) = 1 through a(4) = 14 twice-partitions:
(1) (2) (3) (4)
(11) (21) (22)
(1)(1) (111) (31)
(2)(1) (211)
(11)(1) (1111)
(1)(1)(1) (2)(2)
(3)(1)
(11)(2)
(21)(1)
(11)(11)
(111)(1)
(2)(1)(1)
(11)(1)(1)
(1)(1)(1)(1)
This is the semi-ordered case of
A141199.
For constant instead of weakly decreasing lengths we have
A306319.
For distinct instead of weakly decreasing lengths we have
A358830.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],GreaterEqual@@Length/@#&]],{n,0,10}]
-
P(n,y) = {1/prod(k=1, n, 1 - y*x^k + O(x*x^n))}
seq(n) = {my(g=Vec(P(n,y)-1), v=[1]); for(k=1, n, my(p=g[k], u=v); v=vector(k+1); v[1] = 1 + O(x*x^n); for(j=1, k, v[1+j] = (v[j] + if(jAndrew Howroyd, Dec 31 2022
A358824
Number of twice-partitions of n of odd length.
Original entry on oeis.org
0, 1, 2, 4, 7, 15, 32, 61, 121, 260, 498, 967, 1890, 3603, 6839, 12972, 23883, 44636, 82705, 150904, 275635, 501737, 905498, 1628293, 2922580, 5224991, 9296414, 16482995, 29125140, 51287098, 90171414, 157704275, 275419984, 479683837, 833154673, 1442550486, 2493570655
Offset: 0
The a(1) = 1 through a(5) = 15 twice-partitions:
(1) (2) (3) (4) (5)
(11) (21) (22) (32)
(111) (31) (41)
(1)(1)(1) (211) (221)
(1111) (311)
(2)(1)(1) (2111)
(11)(1)(1) (11111)
(2)(2)(1)
(3)(1)(1)
(11)(2)(1)
(2)(11)(1)
(21)(1)(1)
(11)(11)(1)
(111)(1)(1)
(1)(1)(1)(1)(1)
The version for set partitions is
A024429.
For odd lengths (instead of length) we have
A358334.
The case of odd parts also is
A358823.
The case of odd sums also is
A358826.
The case of odd lengths also is
A358834.
For multiset partitions of integer partitions:
A358837, ranked by
A026424.
A000009 counts partitions into odd parts.
A027193 counts partitions of odd length.
A078408 counts odd-length partitions into odd parts.
A300301 aerated counts twice-partitions with odd sums and parts.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],OddQ[Length[#]]&]],{n,0,10}]
-
R(u,y) = {1/prod(k=1, #u, 1 - u[k]*y*x^k + O(x*x^#u))}
seq(n) = {my(u=vector(n,k,numbpart(k))); Vec(R(u, 1) - R(u, -1), -(n+1))/2} \\ Andrew Howroyd, Dec 30 2022
A358905
Number of sequences of integer partitions with total sum n that are rectangular, meaning all lengths are equal.
Original entry on oeis.org
1, 1, 3, 6, 13, 24, 49, 91, 179, 341, 664, 1280, 2503, 4872, 9557, 18750, 36927, 72800, 143880, 284660, 564093, 1118911, 2221834, 4415417, 8781591, 17476099, 34799199, 69327512, 138176461, 275503854, 549502119, 1096327380, 2187894634, 4367310138, 8719509111
Offset: 0
The a(0) = 1 through a(4) = 13 sequences:
() ((1)) ((2)) ((3)) ((4))
((11)) ((21)) ((22))
((1)(1)) ((111)) ((31))
((1)(2)) ((211))
((2)(1)) ((1111))
((1)(1)(1)) ((1)(3))
((2)(2))
((3)(1))
((11)(11))
((1)(1)(2))
((1)(2)(1))
((2)(1)(1))
((1)(1)(1)(1))
The case of set partitions is
A038041.
The version for weakly decreasing lengths is
A141199, strictly
A358836.
For equal sums instead of lengths we have
A279787.
The case of plane partitions is
A323429.
The case of constant sums also is
A358833.
A055887 counts sequences of partitions with total sum n.
-
ptnseq[n_]:=Join@@Table[Tuples[IntegerPartitions/@comp],{comp,Join@@Permutations/@IntegerPartitions[n]}];
Table[Length[Select[ptnseq[n],SameQ@@Length/@#&]],{n,0,10}]
-
P(n,y) = {1/prod(k=1, n, 1 - y*x^k + O(x*x^n))}
seq(n) = {my(g=P(n,y)); Vec(1 + sum(k=1, n, 1/(1 - polcoef(g, k, y)) - 1))} \\ Andrew Howroyd, Dec 31 2022
A358833
Number of rectangular twice-partitions of n of type (P,R,P).
Original entry on oeis.org
1, 1, 3, 4, 8, 8, 17, 16, 32, 34, 56, 57, 119, 102, 179, 199, 335, 298, 598, 491, 960, 925, 1441, 1256, 2966, 2026, 3726, 3800, 6488, 4566, 11726, 6843, 16176, 14109, 21824, 16688, 49507, 21638, 50286, 50394, 99408, 44584, 165129, 63262, 208853, 205109, 248150
Offset: 0
The a(1) = 1 through a(5) = 8 twice-partitions:
(1) (2) (3) (4) (5)
(11) (21) (22) (32)
(1)(1) (111) (31) (41)
(1)(1)(1) (211) (221)
(1111) (311)
(2)(2) (2111)
(11)(11) (11111)
(1)(1)(1)(1) (1)(1)(1)(1)(1)
This is the rectangular case of
A279787.
This is the case of
A306319 with constant sums.
For distinct instead of constant lengths and sums we have
A358832.
The version for multiset partitions of integer partitions is
A358835.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],SameQ@@Length/@#&&SameQ@@Total/@#&]],{n,0,10}]
-
P(n,y) = {1/prod(k=1, n, 1 - y*x^k + O(x*x^n))}
seq(n) = {my(u=Vec(P(n,y)-1)); concat([1], vector(n, n, sumdiv(n, d, my(p=u[n/d]); sum(j=1, n/d, polcoef(p, j, y)^d))))} \\ Andrew Howroyd, Dec 31 2022
A374704
Number of ways to choose an integer partition of each part of an integer composition of n (A055887) such that the minima are identical.
Original entry on oeis.org
1, 1, 3, 6, 15, 31, 77, 171, 410, 957, 2275, 5370, 12795, 30366, 72307, 172071, 409875, 976155, 2325804, 5541230, 13204161, 31464226, 74980838, 178684715, 425830008, 1014816979, 2418489344, 5763712776, 13736075563, 32735874251, 78016456122, 185929792353, 443110675075
Offset: 0
The a(0) = 1 through a(4) = 15 ways:
() ((1)) ((2)) ((3)) ((4))
((1,1)) ((1,2)) ((1,3))
((1),(1)) ((1,1,1)) ((2,2))
((1),(1,1)) ((1,1,2))
((1,1),(1)) ((2),(2))
((1),(1),(1)) ((1,1,1,1))
((1),(1,2))
((1,2),(1))
((1),(1,1,1))
((1,1),(1,1))
((1,1,1),(1))
((1),(1),(1,1))
((1),(1,1),(1))
((1,1),(1),(1))
((1),(1),(1),(1))
A variation for weakly increasing lengths is
A141199.
For identical sums instead of minima we have
A279787.
For maxima instead of minima, or for unreversed partitions, we have
A358905.
A055887 counts sequences of partitions with total sum n.
Cf.
A000041,
A063834,
A106356,
A189076,
A238343,
A304969,
A305551,
A319066,
A323429,
A333213,
A358833,
A358835.
-
Table[Length[Select[Join@@Table[Tuples[IntegerPartitions/@y], {y,Join@@Permutations/@IntegerPartitions[n]}],SameQ@@Min/@#&]],{n,0,15}]
-
seq(n) = Vec(1 + sum(k=1, n, -1 + 1/(1 - x^k/prod(j=k, n-k, 1 - x^j, 1 + O(x^(n-k+1)))))) \\ Andrew Howroyd, Dec 29 2024
A331638
Number of binary matrices with nonzero rows, a total of n ones and each column with the same number of ones and columns in nonincreasing lexicographic order.
Original entry on oeis.org
1, 3, 5, 16, 17, 140, 65, 1395, 2969, 22176, 1025, 1050766, 4097, 13010328, 128268897, 637598438, 65537, 64864962683, 262145, 1676258452736, 28683380484257, 24908619669860, 4194305, 30567710172480050, 8756434134071649, 62128557507554504, 21271147396968151093
Offset: 1
For constant instead of strict blocks we have
A034729.
Without equal sizes we have
A116540 (normal set multipartitions).
Without strict blocks we have
A317583.
For distinct instead of equal sizes we have
A382428, non-strict blocks
A326517.
For equal sums instead of sizes we have
A382429, non-strict blocks
A326518.
A358832
Number of twice-partitions of n into partitions of distinct lengths and distinct sums.
Original entry on oeis.org
1, 1, 2, 4, 7, 15, 25, 49, 79, 154, 248, 453, 748, 1305, 2125, 3702, 5931, 9990, 16415, 26844, 43246, 70947, 113653, 182314, 292897, 464614, 739640, 1169981, 1844511, 2888427, 4562850, 7079798, 11064182, 17158151, 26676385, 41075556, 63598025, 97420873, 150043132
Offset: 0
The a(1) = 1 through a(5) = 15 twice-partitions:
(1) (2) (3) (4) (5)
(11) (21) (22) (32)
(111) (31) (41)
(11)(1) (211) (221)
(1111) (311)
(21)(1) (2111)
(111)(1) (11111)
(21)(2)
(22)(1)
(3)(11)
(31)(1)
(111)(2)
(211)(1)
(111)(11)
(1111)(1)
This is the case of
A271619 with distinct lengths.
This is the case of
A358830 with distinct sums.
For constant instead of distinct lengths and sums we have
A358833.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],UnsameQ@@Total/@#&&UnsameQ@@Length/@#&]],{n,0,10}]
-
seq(n)={ local(Cache=Map());
my(g=Vec(-1+1/prod(k=1, n, 1 - y*x^k + O(x*x^n))));
my(F(m,r,b) = my(key=[m,r,b], z); if(!mapisdefined(Cache,key,&z),
z = if(r<=0||m==0, r==0, self()(m-1, r, b) + sum(k=1, m, my(c=polcoef(g[m],k)); if(!bittest(b,k)&&c, c*self()(min(m-1,r-m), r-m, bitor(b, 1<Andrew Howroyd, Dec 31 2022
A306318
Number of square twice-partitions of n.
Original entry on oeis.org
1, 1, 1, 1, 2, 2, 4, 5, 10, 12, 19, 24, 39, 49, 73, 104, 151, 212, 317, 443, 638, 936, 1296, 1841, 2635, 3641, 5069, 7176, 9884, 13614, 19113, 26162, 36603, 50405, 70153, 96176, 135388, 184753, 257882, 353587, 494653, 671992, 934905, 1272195, 1762979, 2389255
Offset: 0
The a(10) = 19 square twice-partitions:
((ten)) ((32)(32)) ((211)(111)(111))
((32)(41))
((33)(22))
((33)(31))
((41)(32))
((41)(41))
((42)(22))
((42)(31))
((43)(21))
((44)(11))
((51)(22))
((51)(31))
((52)(21))
((53)(11))
((61)(21))
((62)(11))
((71)(11))
Cf.
A000219,
A001970,
A063834 (twice-partitions),
A089299 (square plane partitions),
A279787,
A305551,
A306017,
A306319 (rectangular twice-partitions),
A319066,
A323429,
A323531 (square partitions of partitions).
-
Table[Sum[Length[Union@@(Tuples[IntegerPartitions[#,{k}]&/@#]&/@IntegerPartitions[n,{k}])],{k,0,Sqrt[n]}],{n,0,20}]
A358827
Number of twice-partitions of n into partitions with all odd lengths and sums.
Original entry on oeis.org
1, 1, 1, 3, 3, 7, 11, 19, 27, 51, 83, 128, 208, 324, 542, 856, 1332, 2047, 3371, 5083, 8009, 12545, 19478, 29770, 46038, 70777, 108627, 167847, 255408, 388751, 593475, 901108, 1361840, 2077973, 3125004, 4729056, 7146843, 10732799, 16104511, 24257261, 36305878
Offset: 0
The a(1) = 1 through a(6) = 11 twice-partitions:
(1) (1)(1) (3) (3)(1) (5) (3)(3)
(111) (111)(1) (221) (5)(1)
(1)(1)(1) (1)(1)(1)(1) (311) (111)(3)
(11111) (221)(1)
(3)(1)(1) (3)(111)
(111)(1)(1) (311)(1)
(1)(1)(1)(1)(1) (111)(111)
(11111)(1)
(3)(1)(1)(1)
(111)(1)(1)(1)
(1)(1)(1)(1)(1)(1)
This is the case of
A358334 with odd sums.
This is the case of
A358825 with odd lengths.
The case of odd length is the odd bisection.
For odd parts instead of lengths and sums we have
A270995.
Requiring odd parts also gives
A279374 aerated.
A000009 counts partitions into odd parts.
A027193 counts partitions of odd length.
A078408 counts odd-length partitions into odd parts.
A300301 aerated counts twice-partitions with odd sums and parts.
-
twiptn[n_]:=Join@@Table[Tuples[IntegerPartitions/@ptn],{ptn,IntegerPartitions[n]}];
Table[Length[Select[twiptn[n],OddQ[Times@@Length/@#]&&OddQ[Times@@Total/@#]&]],{n,0,10}]
Showing 1-10 of 10 results.
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