A374636
Number of integer compositions of n whose leaders of maximal weakly increasing runs are not weakly decreasing.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 1, 3, 10, 28, 72, 178, 425, 985, 2237, 4999, 11016, 24006, 51822, 110983, 236064, 499168, 1050118, 2199304, 4587946, 9537506, 19765213, 40847186, 84205453, 173198096, 355520217, 728426569, 1489977348, 3043054678, 6206298312, 12641504738
Offset: 0
- The maximal weakly increasing runs of y = (1,1,3,2,1) are ((1,1,3),(2),(1)) with leaders (1,2,1) so y is counted under a(8). Also, y matches 1-32 and avoids 23-1.
- The maximal weakly increasing runs of y = (1,3,2,1,1) are ((1,3),(2),(1,1)) with leaders (1,2,1) so y is counted under a(8). Also, y matches 1-32 and avoids 23-1.
- The maximal weakly increasing runs of y = (2,3,1,1,1) are ((2,3),(1,1,1)) with leaders (2,1) so y is not counted under a(8). Also, y avoids 1-32 and matches 23-1.
- The maximal weakly increasing runs of y = (2,3,2,1) are ((2,3),(2),(1)) with leaders (2,2,1) so y is not counted under a(8). Also, y avoids 1-32 and matches 23-1.
- The maximal weakly increasing runs of y = (2,1,3,1,1) are ((2),(1,3),(1,1)) with leaders (2,1,1) so y is not counted under a(8). Also, y avoids both 1-32 and 23-1.
- The maximal weakly increasing runs of y = (2,1,1,3,1) are ((2),(1,1,3),(1)) with leaders (2,1,1) so y is not counted under a(8). Also, y avoids both 1-32 and 23-1.
The a(0) = 0 through a(8) = 10 compositions:
. . . . . . (132) (142) (143)
(1132) (152)
(1321) (1142)
(1232)
(1322)
(1421)
(2132)
(11132)
(11321)
(13211)
The reverse version is the same.
For leaders of identical runs we have
A056823.
The complement is counted by
A189076.
For weakly decreasing runs we have the complement of
A374747.
For leaders of strictly increasing runs we have
A375135, complement
A374697.
A106356 counts compositions by number of maximal anti-runs.
A238279 counts compositions by number of maximal runs
Cf.
A000041,
A188920,
A238343,
A238424,
A333213,
A373949,
A374632,
A374635,
A374678,
A374681,
A375297.
-
Table[Length[Select[Join@@Permutations /@ IntegerPartitions[n],!GreaterEqual@@First/@Split[#,LessEqual]&]],{n,0,15}]
(* or *)
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],MatchQ[#,{_,y_,z_,_,x_,_}/;x
A374682
Number of integer compositions of n whose leaders of anti-runs are weakly decreasing.
Original entry on oeis.org
1, 1, 2, 4, 8, 15, 30, 59, 114, 222, 434, 844, 1641, 3189, 6192, 12020, 23320, 45213, 87624, 169744, 328684, 636221, 1231067, 2381269, 4604713, 8901664
Offset: 0
The a(0) = 1 through a(5) = 15 compositions:
() (1) (2) (3) (4) (5)
(11) (12) (13) (14)
(21) (22) (23)
(111) (31) (32)
(112) (41)
(121) (113)
(211) (131)
(1111) (212)
(221)
(311)
(1112)
(1121)
(1211)
(2111)
(11111)
For reversed partitions instead of compositions we have
A115029.
Other types of runs (instead of anti-):
- For leaders of identical runs we have
A000041.
- For leaders of weakly increasing runs we have
A189076, complement
A374636.
- For leaders of weakly decreasing runs we have
A374747.
- For leaders of strictly decreasing runs we have
A374765.
- For leaders of strictly increasing runs we have
A374697.
Other types of run-leaders (instead of weakly decreasing):
- For weakly increasing leaders we have
A374681.
- For strictly increasing leaders we have
A374679.
- For strictly decreasing leaders we have
A374680.
A106356 counts compositions by number of maximal anti-runs.
A238279 counts compositions by number of maximal runs
A238424 counts partitions whose first differences are an anti-run.
-
Table[Length[Select[Join@@Permutations /@ IntegerPartitions[n],GreaterEqual@@First/@Split[#,UnsameQ]&]],{n,0,15}]
A375135
Number of integer compositions of n whose leaders of maximal strictly increasing runs are not weakly decreasing.
Original entry on oeis.org
0, 0, 0, 0, 0, 1, 3, 9, 25, 63, 152, 355, 809, 1804, 3963, 8590, 18423, 39161, 82620, 173198, 361101, 749326, 1548609, 3189132, 6547190, 13404613, 27378579, 55801506, 113517749, 230544752, 467519136, 946815630, 1915199736, 3869892105, 7812086380, 15756526347
Offset: 0
The composition y = (1,2,1,3,2,3) has strictly increasing runs ((1,2),(1,3),(2,3)), with leaders (1,1,2), which are not weakly decreasing, so y is counted under a(12).
The a(0) = 0 through a(8) = 25 compositions:
. . . . . (122) (132) (133) (143)
(1122) (142) (152)
(1221) (1132) (233)
(1222) (1133)
(1321) (1142)
(2122) (1223)
(11122) (1232)
(11221) (1322)
(12211) (1331)
(1421)
(2132)
(3122)
(11132)
(11222)
(11321)
(12122)
(12212)
(12221)
(13211)
(21122)
(21221)
(111122)
(111221)
(112211)
(122111)
For leaders of constant runs we have
A056823.
For leaders of weakly increasing runs we have
A374636, complement
A189076?
The complement is counted by
A374697.
A335456 counts patterns matched by compositions.
A374700 counts compositions by sum of leaders of strictly increasing runs.
-
Table[Length[Select[Join@@Permutations /@ IntegerPartitions[n], !GreaterEqual@@First/@Split[#,Less]&]],{n,0,15}]
A375139
Numbers k such that the leaders of strictly increasing runs in the k-th composition in standard order are not weakly decreasing.
Original entry on oeis.org
26, 50, 53, 58, 90, 98, 100, 101, 106, 107, 114, 117, 122, 154, 164, 178, 181, 186, 194, 196, 197, 201, 202, 203, 210, 212, 213, 214, 215, 218, 226, 228, 229, 234, 235, 242, 245, 250, 282, 306, 309, 314, 324, 329, 346, 354, 356, 357, 362, 363, 370, 373, 378
Offset: 1
The terms together with corresponding compositions begin:
26: (1,2,2)
50: (1,3,2)
53: (1,2,2,1)
58: (1,1,2,2)
90: (2,1,2,2)
98: (1,4,2)
100: (1,3,3)
101: (1,3,2,1)
106: (1,2,2,2)
107: (1,2,2,1,1)
114: (1,1,3,2)
117: (1,1,2,2,1)
122: (1,1,1,2,2)
154: (3,1,2,2)
164: (2,3,3)
178: (2,1,3,2)
181: (2,1,2,2,1)
186: (2,1,1,2,2)
For leaders of identical runs we have
A335485.
Ranked by positions of non-weakly decreasing rows in
A374683.
The complement is counted by
A374697.
Compositions of this type are counted by
A375135.
A374700 counts compositions by sum of leaders of strictly increasing runs.
All of the following pertain to compositions in standard order:
-
stc[n_]:=Differences[Prepend[Join @@ Position[Reverse[IntegerDigits[n,2]],1],0]]//Reverse;
Select[Range[0,100],!GreaterEqual@@First/@Split[stc[#],Less]&]
Showing 1-4 of 4 results.
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