A110821 SuperRefactorable numbers: m=A005179(n) such that k=m/n is an integer.

1, 2, 12, 24, 36, 60, 180, 240, 360, 720, 1260, 1680, 3600, 5040, 6720, 10080, 15120, 20160, 25200, 32400, 55440, 60480, 100800, 110880, 181440, 221760, 226800, 277200, 665280, 720720, 810000, 907200, 1108800, 1441440, 1587600, 1995840, 2494800, 2882880, 3548160, 3603600

Offset

1,2

Comments

Refactorable numbers, A033950, such that m=A073904(n)=A005179(n).

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

k = m/n = 1, 1, 2, 3, 4, 5, 10, 12, 15, 24, 35, 42, ... is an integer.
For instance: 60/12=5, 180/18=10, 240/20=12, 360/24=15.

Mathematica

t = Table[0, {2^10}]; Do[ d = DivisorSigma[0, n]; If[ d < 2^10 && t[[d]] == 0, t[[d]] = n], {n, 2882880}]; Rest[ Union[ t[[ Select[ Range[2^10], IntegerQ[ t[[ # ]]/# ] &]] ]]] (* Robert G. Wilson v, Sep 21 2005 *)

Crossrefs

Cf. A033950, A005179, A007416 and A073904.

Sequence in context: A144551 A174457 A353011 * A262983 A356078 A324508

Adjacent sequences: A110818 A110819 A110820 * A110822 A110823 A110824

Keyword

nonn

Author

Thomas Ordowski, Sep 16 2005

Extensions

More terms from Robert G. Wilson v, Sep 21 2005

Data corrected by David A. Corneth, Dec 11 2021

Status

approved