A015872 Numbers k such that phi(k + 6) | sigma(k) + 6.

10, 20, 26, 58, 122, 1018, 1040, 2042, 8186, 32762, 522752, 2097146, 8388602, 9898496, 16871744, 33554426, 1073741818, 1630145024

Offset

1,1

Comments

a(19) > 10^12. - Donovan Johnson, Feb 28 2012

Links

Table of n, a(n) for n=1..18.

Mathematica

Select[Range[100000],
Divisible[DivisorSigma[1, #] + 6, EulerPhi[# + 6]] &] (* David Nacin, Feb 2012 *)

Crossrefs

Sequence in context: A229304 A386943 A101869 * A019491 A249989 A175229

Adjacent sequences: A015869 A015870 A015871 * A015873 A015874 A015875

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Offset corrected and a(10)-a(18) from Donovan Johnson, Feb 28 2012

Status

approved