OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..2000
MATHEMATICA
Select[Range[3000], Divisible[DivisorSigma[1, #], EulerPhi[12 + #]] &] (* David Nacin, Mar 03 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved