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A375402
Numbers whose maximal anti-runs of weakly increasing prime factors (with multiplicity) have distinct maxima.
7
1, 2, 3, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 19, 20, 21, 22, 23, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 51, 52, 53, 55, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 89
OFFSET
1,2
COMMENTS
First differs from A349810 in lacking 150.
An anti-run is a sequence with no adjacent equal terms. The maxima of maximal anti-runs in a sequence are obtained by splitting it into maximal anti-run subsequences and taking the greatest term of each.
The partitions with these Heinz numbers are those with (1) no part appearing more than twice and (2) the greatest part appearing only once.
Note the prime factors can alternatively be written in weakly decreasing order.
How is does the sequence relate to A317092? - R. J. Mathar, Aug 20 2024
EXAMPLE
The maximal anti-runs of prime factors of 150 are ((2,3,5),(5)), with maxima (5,5), so 150 is not in the sequence.
The maximal anti-runs of prime factors of 180 are ((2),(2,3),(3,5)), with maxima (2,3,5), so 180 is in the sequence.
The maximal anti-runs of prime factors of 300 are ((2),(2,3,5),(5)), with maxima (2,5,5), so 300 is not in the sequence.
MATHEMATICA
Select[Range[150], UnsameQ@@Max /@ Split[Flatten[ConstantArray@@@FactorInteger[#]], UnsameQ]&]
CROSSREFS
For identical instead of distinct we have A065200, complement A065201.
A version for compositions (instead of partitions) is A374767.
Partitions of this type are counted by A375133.
For minima instead of maxima we have A375398, counted by A375134.
The complement for minima is A375399, counted by A375404.
The complement is A375403, counted by A375401.
A000041 counts integer partitions, strict A000009.
A003242 counts anti-run compositions, ranks A333489.
A number's prime factors (A027746, reverse A238689) have sum A001414, min A020639, max A006530.
A number's prime indices (A112798, reverse A296150) have sum A056239, min A055396, max A061395.
Both have length A001222, distinct A001221.
Sequence in context: A349026 A336360 A102750 * A349810 A317092 A349019
KEYWORD
nonn
AUTHOR
Gus Wiseman, Aug 14 2024
STATUS
approved