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A374640
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Number of integer compositions of n whose leaders of maximal anti-runs are not identical.
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10
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0, 0, 0, 0, 1, 3, 7, 18, 43, 96, 211, 463, 992, 2112, 4462, 9347, 19495, 40480, 83690, 172478, 354455, 726538, 1486024, 3033644, 6182389, 12580486
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OFFSET
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0,6
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COMMENTS
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The leaders of maximal anti-runs in a sequence are obtained by splitting it into maximal consecutive anti-runs (sequences with no adjacent equal terms) and taking the first term of each.
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LINKS
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EXAMPLE
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The a(0) = 0 through a(7) = 18 compositions:
. . . . (211) (122) (411) (133)
(311) (1122) (322)
(2111) (1221) (511)
(2112) (1222)
(2211) (2113)
(3111) (2311)
(21111) (3112)
(3211)
(4111)
(11122)
(11221)
(12211)
(21112)
(21121)
(21211)
(22111)
(31111)
(211111)
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MATHEMATICA
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Table[Length[Select[Join@@Permutations /@ IntegerPartitions[n], !SameQ@@First/@Split[#, UnsameQ]&]], {n, 0, 15}]
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CROSSREFS
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For partitions instead of compositions we have A239955.
A065120 gives leaders of standard compositions.
A106356 counts compositions by number of maximal anti-runs.
A238279 counts compositions by number of maximal runs
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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