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

Author

Labos Elemer, Apr 15 2002

Keywords

• nonn

Comments

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

Crossrefs

Cf. A000203, A000010, A070032.

Programs

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

Formula

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

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