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A096903
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Least integer of each ordered prime signature (A055932) arranged by prime signature (each row starting with least integer of each prime signature, A025487).
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3
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1, 2, 4, 6, 8, 12, 18, 16, 24, 54, 30, 32, 36, 48, 162, 60, 90, 150, 64, 72, 108, 96, 486, 120, 270, 750, 128, 144, 324, 180, 300, 450, 192, 1458, 210, 216, 240, 810, 3750, 256, 288, 972, 360, 540, 600, 1350, 1500, 2250, 384, 4374, 420, 630, 1050, 1470, 432, 648
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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COMMENTS
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There are several other sequences closely related to a(n). A066099 and A108244 both list the associated exponents, while A108730 provides an elegant mapping to binary representations. - Alford Arnold, Mar 05 2006
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LINKS
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EXAMPLE
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Sequence begins
1,
2,
4,
6,
8,
12,18,
16,
24,54,
30,
32,
36,
48,162,
60,90,150
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MATHEMATICA
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SortBy[#, First] &@ Map[Union@ Map[Times @@ MapIndexed[Prime[First@ #2]^#1 &, #] &, Permutations[#]] &, Map[If[# == 1, {0}, Function[f, ReplacePart[Table[0, {PrimePi[f[[-1, 1]]]}], #] &@ Map[PrimePi@ First@ # -> Last@ # &, f]]@ FactorInteger@ #] &, Import["https://oeis.org/A025487/b025487.txt", "Data"][[1 ;; 30, -1]] ] ] // Flatten (* Michael De Vlieger, Feb 06 2020, using b-file from A025487 *)
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CROSSREFS
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KEYWORD
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nonn,tabf
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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