A070033 Least number m such that integer part of sigma(m)/phi(m) equals n.

1, 3, 2, 10, 20, 6, 12, 42, 30, 60, 120, 210, 630, 420, 840, 2520, 10080, 9240, 27720, 55440, 120120, 360360, 720720, 2162160, 6126120, 12252240, 36756720, 116396280, 232792560, 698377680, 2677114440, 5354228880, 26771144400, 155272637520, 465817912560

Offset

1,2

Comments

a(36) <= 1552726375200. a(37) <= 9316358251200. - Donovan Johnson, Oct 18 2012

Links

Table of n, a(n) for n=1..35.

Formula

a(n)=Min{x : Floor[A000203(x)/A000010(x)]=n}

Mathematica

t=Table[0, {100}]; Do[c=Floor[DivisorSigma[1, n]/EulerPhi[n]]; If[c<101&&t[[c]]== 0, t[[c]]=n], {n, 1, 100000}]; t

Crossrefs

Cf. A000203, A000010, A070032.

Sequence in context: A192617 A082219 A034461 * A107334 A335719 A096073

Adjacent sequences: A070030 A070031 A070032 * A070034 A070035 A070036

Keyword

nonn

Author

Labos Elemer, Apr 15 2002

Extensions

Two more terms from Labos Elemer, May 18 2004

a(30)-a(33) from Donovan Johnson, Apr 14 2010

a(34)-a(35) from Donovan Johnson, Oct 18 2012

Status

approved