A015804 - OEIS

A015804

Numbers k such that phi(k) + 11 | sigma(k).

8, 25, 34, 50, 304, 432, 1700, 1968, 2400, 2656, 13504, 44736, 59776, 1025536, 4148224, 12512256, 16685056, 66924544, 201043968, 51535085568, 68713578496

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OFFSET

1,1

COMMENTS

a(22) > 10^12. - Donovan Johnson, Feb 28 2012

LINKS

Table of n, a(n) for n=1..21.

MATHEMATICA

Select[Range[100000],

Divisible[DivisorSigma[1, #], EulerPhi[#] + 11] &] (* David Nacin, Feb 28 2012 *)

CROSSREFS

Sequence in context: A239583 A042611 A160758 * A352978 A302424 A244276

Adjacent sequences: A015801 A015802 A015803 * A015805 A015806 A015807

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

EXTENSIONS

a(11)-a(21) from Donovan Johnson, Feb 28 2012

STATUS

approved