OFFSET
0,3
COMMENTS
The weakly decreasing run-leaders of a sequence are obtained by splitting it into maximal weakly decreasing subsequences and taking the first term of each.
LINKS
EXAMPLE
The a(0) = 1 through a(4) = 24 compositions:
() (11) (22) (33) (44)
(211) (321) (422)
(1122) (431)
(1221) (1133)
(3111) (1322)
(11112) (1331)
(11121) (4211)
(11211) (11132)
(12111) (11321)
(13211)
(21122)
(21221)
(22112)
(22121)
(41111)
(111113)
(111131)
(111311)
(113111)
(131111)
(211112)
(211121)
(211211)
(212111)
MATHEMATICA
Table[Length[Select[Join@@Permutations /@ IntegerPartitions[2n], Total[First/@Split[#, GreaterEqual]]==n&]], {n, 0, 8}]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Aug 12 2024
STATUS
approved