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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).
3

%I #23 Feb 06 2020 20:54:21

%S 1,2,4,6,8,12,18,16,24,54,30,32,36,48,162,60,90,150,64,72,108,96,486,

%T 120,270,750,128,144,324,180,300,450,192,1458,210,216,240,810,3750,

%U 256,288,972,360,540,600,1350,1500,2250,384,4374,420,630,1050,1470,432,648

%N Least integer of each ordered prime signature (A055932) arranged by prime signature (each row starting with least integer of each prime signature, A025487).

%C 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

%H Michael De Vlieger, <a href="/A096903/b096903.txt">Table of n, a(n) for n = 0..14264</a> (rows 0 <= n <= 487 = A098719(9) - 1.)

%H OEIS Wiki, <a href="http://oeis.org/wiki/Orderings_of_ordered_prime_signatures">Orderings of ordered prime signatures</a>

%e Sequence begins

%e 1,

%e 2,

%e 4,

%e 6,

%e 8,

%e 12,18,

%e 16,

%e 24,54,

%e 30,

%e 32,

%e 36,

%e 48,162,

%e 60,90,150

%t 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 *)

%Y Cf. A025487, A055932, A066099, A108244, A108730.

%K nonn,tabf

%O 0,2

%A _Ray Chandler_, Aug 01 2004

%E Edited by _Daniel Forgues_, Jan 24 2011