A384175
Number of subsets of {1..n} with all distinct lengths of maximal runs (increasing by 1).
Original entry on oeis.org
1, 2, 4, 7, 13, 24, 44, 77, 135, 236, 412, 713, 1215, 2048, 3434, 5739, 9559, 15850, 26086, 42605, 69133, 111634, 179602, 288069, 460553, 733370, 1162356, 1833371, 2878621, 4501856, 7016844, 10905449, 16904399, 26132460, 40279108, 61885621, 94766071, 144637928
Offset: 0
The subset {2,3,5,6,7,9} has maximal runs ((2,3),(5,6,7),(9)), with lengths (2,3,1), so is counted under a(9).
The a(0) = 1 through a(4) = 13 subsets:
{} {} {} {} {}
{1} {1} {1} {1}
{2} {2} {2}
{1,2} {3} {3}
{1,2} {4}
{2,3} {1,2}
{1,2,3} {2,3}
{3,4}
{1,2,3}
{1,2,4}
{1,3,4}
{2,3,4}
{1,2,3,4}
For equal instead of distinct lengths we have
A243815.
These subsets are ranked by
A328592.
The complement is counted by
A384176.
For permutations instead of subsets we have
A384891, equal instead of distinct
A384892.
A034839 counts subsets by number of maximal runs, for strict partitions
A116674.
A098859 counts Wilf partitions (distinct multiplicities), complement
A336866.
Cf.
A000009,
A010027,
A044813,
A047993,
A242882,
A325325,
A329739,
A351202,
A383013,
A384889,
A384890.
-
Table[Length[Select[Subsets[Range[n]],UnsameQ@@Length/@Split[#,#2==#1+1&]&]],{n,0,10}]
-
lista(n)={my(o=(1-x^(n+1))/(1-x)*O(y^(n+2)),p=prod(i=1,n,1+o+x*y^(i+1)/(1-y),1/(1-y)));p=subst(serlaplace(p),x,1);Vec(p-1)} \\ Christian Sievers, Jun 18 2025
A384893
Triangle read by rows where T(n,k) is the number of subsets of {1..n} with k maximal anti-runs (increasing by more than 1).
Original entry on oeis.org
1, 1, 1, 1, 2, 1, 1, 4, 2, 1, 1, 7, 5, 2, 1, 1, 12, 10, 6, 2, 1, 1, 20, 20, 13, 7, 2, 1, 1, 33, 38, 29, 16, 8, 2, 1, 1, 54, 71, 60, 39, 19, 9, 2, 1, 1, 88, 130, 122, 86, 50, 22, 10, 2, 1, 1, 143, 235, 241, 187, 116, 62, 25, 11, 2, 1, 1, 232, 420, 468, 392, 267, 150, 75, 28, 12, 2, 1
Offset: 0
The subset {3,6,7,9,11,12} has maximal anti-runs ((3,6),(7,9,11),(12)), so is counted under T(12,3).
The subset {3,6,7,9,10,12} has maximal anti-runs ((3,6),(7,9),(10,12)), so is counted under T(12,3).
Row n = 5 counts the following subsets:
{} {1} {1,2} {1,2,3} {1,2,3,4} {1,2,3,4,5}
{2} {2,3} {2,3,4} {2,3,4,5}
{3} {3,4} {3,4,5}
{4} {4,5} {1,2,3,5}
{5} {1,2,4} {1,2,4,5}
{1,3} {1,2,5} {1,3,4,5}
{1,4} {1,3,4}
{1,5} {1,4,5}
{2,4} {2,3,5}
{2,5} {2,4,5}
{3,5}
{1,3,5}
Triangle begins:
1
1 1
1 2 1
1 4 2 1
1 7 5 2 1
1 12 10 6 2 1
1 20 20 13 7 2 1
1 33 38 29 16 8 2 1
1 54 71 60 39 19 9 2 1
1 88 130 122 86 50 22 10 2 1
1 143 235 241 187 116 62 25 11 2 1
1 232 420 468 392 267 150 75 28 12 2 1
1 376 744 894 806 588 363 188 89 31 13 2 1
For runs instead of anti-runs we have
A034839, for strict partitions
A116674.
For integer partitions instead of subsets we have
A268193, strict
A384905.
A384175 counts subsets with all distinct lengths of maximal runs, complement
A384176.
A384877 gives lengths of maximal anti-runs in binary indices, firsts
A384878.
-
Table[Length[Select[Subsets[Range[n]],Length[Split[#,#2!=#1+1&]]==k&]],{n,0,10},{k,0,n}]
A384877
Irregular triangle read by rows where row k lists the lengths of maximal anti-runs (increasing by more than 1) in the binary indices of n.
Original entry on oeis.org
1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 2, 3, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 2, 3, 1, 2, 1, 1, 2, 2, 3, 3, 1, 3, 1, 2, 2, 2
Offset: 0
The binary indices of 182 are {2,3,5,6,8}, with maximal anti-runs ((2),(3,5),(6,8)) so row 182 is (1,2,2).
Triangle begins:
0: ()
1: (1)
2: (1)
3: (1,1)
4: (1)
5: (2)
6: (1,1)
7: (1,1,1)
8: (1)
9: (2)
10: (2)
11: (1,2)
12: (1,1)
13: (2,1)
14: (1,1,1)
15: (1,1,1,1)
Positions of rows of the form (1,1,...) are
A023758.
Positions of first appearances of each distinct row appear to be
A052499.
A355394 counts partitions without a neighborless part, singleton case
A355393.
A356606 counts strict partitions without a neighborless part, complement
A356607.
A384175 counts subsets with all distinct lengths of maximal runs, complement
A384176.
Cf.
A044813,
A048793,
A069010,
A164707,
A243815,
A246029,
A328592,
A384177,
A384877,
A384879,
A384893.
-
bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n,2]],1];
Table[Length/@Split[bpe[n],#2!=#1+1&],{n,0,100}]
A384890
Number of maximal anti-runs (increasing by more than 1) in the binary indices of n.
Original entry on oeis.org
0, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 1, 1, 1, 2, 1, 1, 2, 3, 2, 2, 2, 3, 3, 3, 4, 5, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 2, 2, 2, 3, 2, 2, 3, 4, 3, 3, 3, 4, 4, 4, 5, 6, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 1, 1, 1, 2, 1, 1, 2
Offset: 0
The binary indices of 51 are {1,2,5,6}, with maximal anti-runs ((1),(2,5),(6)), so a(51) = 3.
For prime indices instead of binary indices we have
A384906.
A356606 counts strict partitions without a neighborless part, complement
A356607.
A384175 counts subsets with all distinct lengths of maximal runs, complement
A384176.
-
bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n,2]],1];
Table[Length[Split[bpe[n],#2!=#1+1&]],{n,0,100}]
A384176
Number of subsets of {1..n} without all distinct lengths of maximal runs (increasing by 1).
Original entry on oeis.org
0, 0, 0, 1, 3, 8, 20, 51, 121, 276, 612, 1335, 2881, 6144, 12950, 27029, 55977, 115222, 236058, 481683, 979443
Offset: 0
The subset {1,3,4,8,9} has maximal runs ((1),(3,4),(8,9)), with lengths (1,2,2), so is counted under a(10).
The a(0) = 0 through a(6) = 20 subsets:
. . . {1,3} {1,3} {1,3} {1,3}
{1,4} {1,4} {1,4}
{2,4} {1,5} {1,5}
{2,4} {1,6}
{2,5} {2,4}
{3,5} {2,5}
{1,3,5} {2,6}
{1,2,4,5} {3,5}
{3,6}
{4,6}
{1,3,5}
{1,3,6}
{1,4,6}
{2,4,6}
{1,2,4,5}
{1,2,4,6}
{1,2,5,6}
{1,3,4,6}
{1,3,5,6}
{2,3,5,6}
For equal instead of distinct lengths the complement is
A243815.
These subsets are ranked by the non-members of
A328592.
The complement is counted by
A384175.
A034839 counts subsets by number of maximal runs, for strict partitions
A116674.
A098859 counts Wilf partitions (distinct multiplicities), complement
A336866.
-
Table[Length[Select[Subsets[Range[n]],!UnsameQ@@Length/@Split[#,#2==#1+1&]&]],{n,0,10}]
A384905
Triangle read by rows where T(n,k) is the number of strict integer partitions of n with k maximal anti-runs (decreasing by more than 1).
Original entry on oeis.org
1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 2, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 3, 0, 1, 0, 0, 0, 0, 3, 2, 0, 0, 0, 0, 0, 0, 4, 2, 0, 0, 0, 0, 0, 0, 0, 5, 2, 1, 0, 0, 0, 0, 0, 0, 0, 6, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 7, 4, 1, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0
The T(10,2) = 3 strict partitions with 2 maximal anti-runs are: (7,2,1), (5,4,1), (5,3,2).
Triangle begins:
1
0 1
0 1 0
0 1 1 0
0 2 0 0 0
0 2 1 0 0 0
0 3 0 1 0 0 0
0 3 2 0 0 0 0 0
0 4 2 0 0 0 0 0 0
0 5 2 1 0 0 0 0 0 0
0 6 3 0 1 0 0 0 0 0 0
0 7 4 1 0 0 0 0 0 0 0 0
0 9 3 3 0 0 0 0 0 0 0 0 0
This is the strict case of
A268193.
A384175 counts subsets with all distinct lengths of maximal runs, complement
A384176.
A384877 gives lengths of maximal anti-runs in binary indices, firsts
A384878.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&Length[Split[#,#1!=#2+1&]]==k&]],{n,0,10},{k,0,n}]
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}]
A243815
Number of length n words on alphabet {0,1} such that the length of every maximal block of 0's (runs) is the same.
Original entry on oeis.org
1, 2, 4, 8, 14, 24, 39, 62, 97, 151, 233, 360, 557, 864, 1344, 2099, 3290, 5176, 8169, 12931, 20524, 32654, 52060, 83149, 133012, 213069, 341718, 548614, 881572, 1417722, 2281517, 3673830, 5918958, 9540577, 15384490, 24817031, 40045768, 64637963, 104358789
Offset: 0
0110 is a "good" word because the length of both its runs of 0's is 1.
Words of the form 11...1 are good words because the condition is vacuously satisfied.
a(5) = 24 because there are 32 length 5 binary words but we do not count: 00010, 00101, 00110, 01000, 01001, 01100, 10010, 10100.
For distinct instead of equal lengths we have
A384175, complement
A384176.
For anti-runs instead of runs we have
A384889, for partitions
A384888.
For permutations instead of subsets we have
A384892, distinct instead of equal
A384891.
The complement is counted by
A385214.
A034839 counts subsets by number of maximal runs, for strict partitions
A116674.
A384887 counts partitions with equal lengths of gapless runs, distinct
A384884.
-
a:= n-> 1 + add(add((d-> binomial(d+j, d))(n-(i*j-1))
, j=1..iquo(n+1, i)), i=2..n+1):
seq(a(n), n=0..50); # Alois P. Heinz, Jun 11 2014
-
nn=30;Prepend[Map[Total,Transpose[Table[Drop[CoefficientList[Series[ (1+x^k)/(1-x-x^(k+1))-1/(1-x),{x,0,nn}],x],1],{k,1,nn}]]],0]+1
Table[Length[Select[Subsets[Range[n]],SameQ@@Length/@Split[#,#2==#1+1&]&]],{n,0,10}] (* Gus Wiseman, Jun 23 2025 *)
A384879
Numbers whose binary indices have all distinct lengths of maximal anti-runs (increasing by more than 1).
Original entry on oeis.org
1, 2, 4, 5, 8, 9, 10, 11, 13, 16, 17, 18, 19, 20, 21, 22, 25, 26, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 49, 50, 52, 53, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 80, 81, 82, 83, 84, 85, 86, 88, 97, 98, 100, 101, 104, 105, 106, 128, 129, 130
Offset: 1
The binary indices of 813 are {1,3,4,6,9,10}, with maximal anti-runs ((1,3),(4,6,9),(10)), with lengths (2,3,1), so 813 is in the sequence.
The terms together with their binary expansions and binary indices begin:
1: 1 ~ {1}
2: 10 ~ {2}
4: 100 ~ {3}
5: 101 ~ {1,3}
8: 1000 ~ {4}
9: 1001 ~ {1,4}
10: 1010 ~ {2,4}
11: 1011 ~ {1,2,4}
13: 1101 ~ {1,3,4}
16: 10000 ~ {5}
17: 10001 ~ {1,5}
18: 10010 ~ {2,5}
19: 10011 ~ {1,2,5}
20: 10100 ~ {3,5}
21: 10101 ~ {1,3,5}
22: 10110 ~ {2,3,5}
25: 11001 ~ {1,4,5}
26: 11010 ~ {2,4,5}
A098859 counts Wilf partitions (distinct multiplicities), complement
A336866.
A356606 counts strict partitions without a neighborless part, complement
A356607.
Cf.
A023758,
A044813,
A048793,
A164707,
A242882,
A243815,
A325325,
A328592,
A384879,
A384884,
A384886,
A384893.
-
bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n,2]],1];
Select[Range[100],UnsameQ@@Length/@Split[bpe[#],#2!=#1+1&]&]
A384880
Number of strict integer partitions of n with all distinct lengths of maximal anti-runs (decreasing by more than 1).
Original entry on oeis.org
1, 1, 1, 1, 2, 2, 3, 4, 6, 6, 9, 10, 12, 15, 18, 21, 25, 30, 34, 41, 46, 55, 63, 75, 85, 99, 114, 133, 152, 178, 201, 236, 269, 308, 352, 404, 460, 525, 594, 674, 763, 865, 974, 1098, 1236, 1385, 1558, 1745, 1952, 2181, 2435, 2712, 3026, 3363, 3740, 4151, 4612
Offset: 0
The strict partition y = (10,7,6,4,2,1) has maximal anti-runs ((10,7),(6,4,2),(1)), with lengths (2,3,1), so y is counted under a(30).
The a(1) = 1 through a(14) = 18 partitions (A-E = 10-14):
1 2 3 4 5 6 7 8 9 A B C D E
31 41 42 52 53 63 64 74 75 85 86
51 61 62 72 73 83 84 94 95
421 71 81 82 92 93 A3 A4
431 531 91 A1 A2 B2 B3
521 621 532 542 B1 C1 C2
541 632 642 643 D1
631 641 651 652 653
721 731 732 742 743
821 741 751 752
831 832 761
921 841 842
931 851
A21 932
6421 941
A31
B21
7421
For subsets instead of strict partitions we have
A384177.
For runs instead of anti-runs we have
A384178.
This is the strict case of
A384885.
A047993 counts partitions with max part = length.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&UnsameQ@@Length/@Split[#,#2<#1-1&]&]],{n,0,30}]
Showing 1-10 of 26 results.
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