A384884
Number of integer partitions of n with all distinct lengths of maximal gapless runs (decreasing by 0 or 1).
Original entry on oeis.org
1, 1, 2, 3, 4, 6, 9, 13, 18, 25, 35, 46, 60, 79, 104, 131, 170, 215, 271, 342, 431, 535, 670, 830, 1019, 1258, 1547, 1881, 2298, 2787, 3359, 4061, 4890, 5849, 7010, 8361, 9942, 11825, 14021, 16558, 19561, 23057, 27084, 31821, 37312, 43627, 50999, 59500, 69267
Offset: 0
The partition y = (6,6,4,3,3,2) has maximal gapless runs ((6,6),(4,3,3,2)), with lengths (2,4), so y is counted under a(24).
The a(1) = 1 through a(8) = 18 partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (21) (22) (32) (33) (43) (44)
(111) (211) (221) (222) (322) (332)
(1111) (311) (321) (331) (422)
(2111) (411) (421) (431)
(11111) (2211) (511) (521)
(3111) (2221) (611)
(21111) (3211) (2222)
(111111) (4111) (3221)
(22111) (4211)
(31111) (5111)
(211111) (22211)
(1111111) (32111)
(41111)
(221111)
(311111)
(2111111)
(11111111)
For subsets instead of strict partitions we have
A384175.
For equal instead of distinct lengths we have
A384887.
A098859 counts Wilf partitions (distinct multiplicities), complement
A336866.
A355394 counts partitions without a neighborless part, singleton case
A355393.
A356236 counts partitions with a neighborless part, singleton case
A356235.
A356606 counts strict partitions without a neighborless part, complement
A356607.
Cf.
A008284,
A044813,
A047993,
A242882,
A287170,
A325324,
A325325,
A356226,
A356230,
A356233,
A356234,
A384176,
A384177,
A384886.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@Length/@Split[#,#2>=#1-1&]&]],{n,0,15}]
A324518
Number of integer partitions of n > 0 where the maximum part equals the length minus the number of distinct parts.
Original entry on oeis.org
0, 1, 0, 0, 1, 2, 2, 0, 3, 1, 6, 7, 7, 9, 11, 10, 16, 26, 22, 42, 43, 54, 61, 83, 85, 118, 135, 179, 201, 263, 297, 371, 445, 510, 608, 732, 886, 1009, 1231, 1442, 1721, 2015, 2416, 2750, 3327, 3784, 4542, 5190, 6142, 7044, 8315, 9573, 11203, 12913, 15056
Offset: 1
The a(2) = 1 through a(12) = 7 integer partitions:
(11) (2111) (222) (2221) (33111) (322111) (32222) (3333)
(2211) (31111) (321111) (33311) (33222)
(411111) (322211) (322221)
(332111) (332211)
(4211111) (441111)
(5111111) (4221111)
(4311111)
A326842
Number of integer partitions of n whose parts all divide n and whose length also divides n.
Original entry on oeis.org
1, 1, 2, 2, 3, 2, 5, 2, 5, 3, 5, 2, 21, 2, 5, 6, 9, 2, 22, 2, 21, 6, 5, 2, 134, 3, 5, 6, 23, 2, 157, 2, 27, 6, 5, 6, 478, 2, 5, 6, 208, 2, 224, 2, 31, 63, 5, 2, 1720, 3, 30, 6, 34, 2, 322, 6, 295, 6, 5, 2, 13899, 2, 5, 68, 126, 8, 429, 2, 42, 6, 358, 2, 19959, 2
Offset: 0
The a(1) = 1 through a(8) = 5 partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (111) (22) (11111) (33) (1111111) (44)
(1111) (222) (2222)
(321) (4211)
(111111) (11111111)
The a(12) = 21 partitions:
(12)
(6,6)
(4,4,4)
(6,3,3)
(6,4,2)
(3,3,3,3)
(4,3,3,2)
(4,4,2,2)
(4,4,3,1)
(6,2,2,2)
(6,3,2,1)
(6,4,1,1)
(2,2,2,2,2,2)
(3,2,2,2,2,1)
(3,3,2,2,1,1)
(3,3,3,1,1,1)
(4,2,2,2,1,1)
(4,3,2,1,1,1)
(4,4,1,1,1,1)
(6,2,1,1,1,1)
(1,1,1,1,1,1,1,1,1,1,1,1)
Partitions using divisors are
A018818.
Partitions whose length divides their sum are
A067538.
-
Table[Length[Select[IntegerPartitions[n,All,Divisors[n]],Divisible[n,Length[#]]&]],{n,1,30}]
A340602
Heinz numbers of integer partitions of even rank.
Original entry on oeis.org
1, 2, 5, 6, 8, 9, 11, 14, 17, 20, 21, 23, 24, 26, 30, 31, 32, 35, 36, 38, 39, 41, 44, 45, 47, 49, 50, 54, 56, 57, 58, 59, 65, 66, 67, 68, 73, 74, 75, 80, 81, 83, 84, 86, 87, 91, 92, 95, 96, 97, 99, 102, 103, 104, 106, 109, 110, 111, 120, 122, 124, 125, 126, 127
Offset: 1
The sequence of partitions with their Heinz numbers begins:
1: () 31: (11) 58: (10,1)
2: (1) 32: (1,1,1,1,1) 59: (17)
5: (3) 35: (4,3) 65: (6,3)
6: (2,1) 36: (2,2,1,1) 66: (5,2,1)
8: (1,1,1) 38: (8,1) 67: (19)
9: (2,2) 39: (6,2) 68: (7,1,1)
11: (5) 41: (13) 73: (21)
14: (4,1) 44: (5,1,1) 74: (12,1)
17: (7) 45: (3,2,2) 75: (3,3,2)
20: (3,1,1) 47: (15) 80: (3,1,1,1,1)
21: (4,2) 49: (4,4) 81: (2,2,2,2)
23: (9) 50: (3,3,1) 83: (23)
24: (2,1,1,1) 54: (2,2,2,1) 84: (4,2,1,1)
26: (6,1) 56: (4,1,1,1) 86: (14,1)
30: (3,2,1) 57: (8,2) 87: (10,2)
Taking only maximum part gives
A061395.
These partitions are counted by
A340601.
The case of positive rank is
A340605.
- Rank -
A257541 gives the rank of the partition with Heinz number n.
A324516 counts partitions with rank = maximum minus minimum part (
A324515).
A340653 counts factorizations of rank 0.
- Even -
A024430 counts set partitions of even length.
A034008 counts compositions of even length.
A052841 counts ordered set partitions of even length.
A339846 counts factorizations of even length.
Cf.
A000041,
A006141,
A056239,
A072233,
A112798,
A168659,
A325134,
A326836,
A326845,
A340386,
A340387.
A351204
Number of integer partitions of n such that every permutation has all distinct runs.
Original entry on oeis.org
1, 1, 2, 3, 4, 5, 8, 9, 11, 14, 18, 20, 25, 28, 34, 41, 47, 53, 64, 72, 84, 98, 113, 128, 148, 169, 194, 223, 255, 289, 333, 377, 428, 488, 554, 629, 715, 807, 913, 1033, 1166, 1313, 1483, 1667, 1875, 2111, 2369, 2655, 2977, 3332, 3729, 4170, 4657, 5195, 5797, 6459
Offset: 0
The a(1) = 1 through a(8) = 11 partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (21) (22) (32) (33) (43) (44)
(111) (31) (41) (42) (52) (53)
(1111) (2111) (51) (61) (62)
(11111) (222) (421) (71)
(321) (2221) (431)
(3111) (4111) (521)
(111111) (211111) (2222)
(1111111) (5111)
(311111)
(11111111)
The version for run-lengths instead of runs is
A000005.
The version for normal multisets is 2^(n-1) -
A283353(n-3).
A005811 counts runs in binary expansion.
A044813 lists numbers whose binary expansion has distinct run-lengths.
A098859 counts partitions with distinct multiplicities, ordered
A242882.
A297770 counts distinct runs in binary expansion.
A003242 counts anti-run compositions.
Counting words with all distinct runs:
-
A351202 = permutations of prime factors.
-
Table[Length[Select[IntegerPartitions[n],Select[Permutations[#],!UnsameQ@@Split[#]&]=={}&]],{n,0,15}]
-
\\ here Q(n) is A000009.
Q(n)={polcoef(prod(k=1, n, 1 + x^k + O(x*x^n)), n)}
a(n)={Q(n) + if(n, numdiv(n) - 1) + sum(k=1, (n-1)\3, sum(j=3, (n-1)\k, j%2==1 && n-k*j<>k))} \\ Andrew Howroyd, Feb 15 2022
A098123
Number of compositions of n with equal number of even and odd parts.
Original entry on oeis.org
1, 0, 0, 2, 0, 4, 6, 6, 24, 28, 60, 130, 190, 432, 770, 1386, 2856, 5056, 9828, 18918, 34908, 68132, 128502, 244090, 470646, 890628, 1709136, 3271866, 6238986, 11986288, 22925630, 43932906, 84349336, 161625288, 310404768, 596009494
Offset: 0
From _Gus Wiseman_, Jun 26 2022: (Start)
The a(0) = 1 through a(7) = 6 compositions (empty columns indicated by dots):
() . . (12) . (14) (1122) (16)
(21) (23) (1212) (25)
(32) (1221) (34)
(41) (2112) (43)
(2121) (52)
(2211) (61)
(End)
These compositions are ranked by
A355321.
A340597
Numbers with an alt-balanced factorization.
Original entry on oeis.org
4, 12, 18, 27, 32, 48, 64, 72, 80, 96, 108, 120, 128, 144, 160, 180, 192, 200, 240, 256, 270, 288, 300, 320, 360, 384, 400, 405, 432, 448, 450, 480, 500, 540, 576, 600, 640, 648, 672, 675, 720, 750, 768, 800, 864, 896, 900, 960, 972, 1000, 1008, 1024, 1080
Offset: 1
The sequence of terms together with their prime signatures begins:
4: (2) 180: (2,2,1) 450: (1,2,2)
12: (2,1) 192: (6,1) 480: (5,1,1)
18: (1,2) 200: (3,2) 500: (2,3)
27: (3) 240: (4,1,1) 540: (2,3,1)
32: (5) 256: (8) 576: (6,2)
48: (4,1) 270: (1,3,1) 600: (3,1,2)
64: (6) 288: (5,2) 640: (7,1)
72: (3,2) 300: (2,1,2) 648: (3,4)
80: (4,1) 320: (6,1) 672: (5,1,1)
96: (5,1) 360: (3,2,1) 675: (3,2)
108: (2,3) 384: (7,1) 720: (4,2,1)
120: (3,1,1) 400: (4,2) 750: (1,1,3)
128: (7) 405: (4,1) 768: (8,1)
144: (4,2) 432: (4,3) 800: (5,2)
160: (5,1) 448: (6,1) 864: (5,3)
For example, there are two alt-balanced factorizations of 480, namely (2*3*4*4*5) and (2*2*2*2*5*6), so 480 in the sequence.
Numbers with a balanced factorization are
A100959.
These factorizations are counted by
A340599.
The twice-balanced version is
A340657.
A045778 counts strict factorizations.
A316439 counts factorizations by product and length.
Other balance-related sequences:
-
A010054 counts balanced strict partitions.
-
A047993 counts balanced partitions.
-
A098124 counts balanced compositions.
-
A106529 lists Heinz numbers of balanced partitions.
-
A340596 counts co-balanced factorizations.
-
A340598 counts balanced set partitions.
-
A340600 counts unlabeled balanced multiset partitions.
-
A340653 counts balanced factorizations.
-
A340654 counts cross-balanced factorizations.
-
A340655 counts twice-balanced factorizations.
Cf.
A006141,
A064174,
A117409,
A200750,
A303975,
A324518,
A324522,
A325134,
A340607,
A340608,
A340611,
A340656.
-
facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
Select[Range[100],Select[facs[#],Length[#]==Max[#]&]!={}&]
A340692
Number of integer partitions of n of odd rank.
Original entry on oeis.org
0, 0, 2, 0, 4, 2, 8, 4, 14, 12, 26, 22, 44, 44, 76, 78, 126, 138, 206, 228, 330, 378, 524, 602, 814, 950, 1252, 1466, 1900, 2238, 2854, 3362, 4236, 5006, 6232, 7356, 9078, 10720, 13118, 15470, 18800, 22152, 26744, 31456, 37772, 44368, 53002, 62134, 73894
Offset: 0
The a(0) = 0 through a(9) = 12 partitions (empty columns indicated by dots):
. . (2) . (4) (32) (6) (52) (8) (54)
(11) (31) (221) (33) (421) (53) (72)
(211) (51) (3211) (71) (432)
(1111) (222) (22111) (422) (441)
(411) (431) (621)
(3111) (611) (3222)
(21111) (3221) (3321)
(111111) (3311) (5211)
(5111) (22221)
(22211) (42111)
(41111) (321111)
(311111) (2211111)
(2111111)
(11111111)
Note: A-numbers of Heinz-number sequences are in parentheses below.
The Heinz numbers of these partitions are (
A340603).
A072233 counts partitions by sum and length.
A168659 counts partitions whose length is divisible by maximum.
A200750 counts partitions whose length and maximum are relatively prime.
- Rank -
A257541 gives the rank of the partition with Heinz number n.
- Odd -
A026804 counts partitions whose least part is odd.
A339890 counts factorizations of odd length.
Cf.
A003114,
A006141,
A027187,
A039900,
A067538,
A096401,
A117409,
A143773,
A324518,
A325134,
A340828,
A340854/
A340855.
-
Table[Length[Select[IntegerPartitions[n],OddQ[Max[#]-Length[#]]&]],{n,0,30}]
A096401
Number of balanced partitions of n into distinct parts: least part is equal to number of parts.
Original entry on oeis.org
1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 8, 8, 10, 11, 13, 14, 17, 18, 21, 23, 26, 28, 32, 35, 39, 43, 48, 53, 59, 65, 72, 80, 88, 97, 107, 118, 129, 142, 155, 171, 186, 204, 222, 244, 265, 290, 315, 345, 374, 409, 443, 484, 524, 571, 618, 673, 727, 790
Offset: 1
a(14)=3 because we have 12+2, 7+4+3 and 6+5+3.
-
G:=sum((x^(m*(3*m-1)/2)-x^(m*(3*m+1)/2))/product(1-x^i,i=1..m),m=1..20): Gser:=series(G,x=0,80): seq(coeff(Gser,x^n),n=1..78); # Emeric Deutsch, Mar 29 2005
-
my(N=99, x='x+O('x^N)); Vec(sum(k=1, N, x^(k*(3*k-1)/2)/prod(j=1, k-1, 1-x^j))) \\ Seiichi Manyama, Jan 15 2022
A098124
Number of compositions of n in which the largest part is equal to the number of parts.
Original entry on oeis.org
1, 0, 2, 1, 3, 6, 10, 15, 30, 54, 92, 160, 282, 492, 859, 1490, 2570, 4428, 7627, 13098, 22421, 38290, 65265, 111018, 188475, 319380, 540266, 912397, 1538371, 2589858, 4353820, 7309362, 12255474, 20523307, 34328731, 57357184, 95733131, 159626049
Offset: 1
a(7)=10 because we have 223, 232, 322, 133, 313, 331, 1114, 1141, 1411 and 4111.
-
G:=sum(((x^(k+1)-x)^k-(x^k-x)^k)/(x-1)^k,k=1..25):Gser:=series(G,x=0,45):seq(coeff(Gser,x^n),n=1..42); # Emeric Deutsch, Apr 16 2005
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