A096903 - OEIS

A096903

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

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)

OFFSET

0,2

COMMENTS

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

LINKS

Michael De Vlieger, Table of n, a(n) for n = 0..14264 (rows 0 <= n <= 487 = A098719(9) - 1.)

OEIS Wiki, Orderings of ordered prime signatures

EXAMPLE

Sequence begins

12,18,

16,

24,54,

30,

32,

36,

48,162,

60,90,150

MATHEMATICA

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 *)

CROSSREFS

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

Sequence in context: A168657 A240498 A081954 * A352107 A273457 A222603

Adjacent sequences: A096900 A096901 A096902 * A096904 A096905 A096906

KEYWORD

nonn,tabf

AUTHOR

Ray Chandler, Aug 01 2004

EXTENSIONS

Edited by Daniel Forgues, Jan 24 2011

STATUS

approved