OFFSET
1,2
COMMENTS
No more terms < 58000. - Emeric Deutsch, Jul 25 2006
EXAMPLE
The digits of sigma(3735)^phi(3735) sum to 33615 and 33615 is divisible by 3735, so 3735 is in the sequence.
MAPLE
with(numtheory): sd:=proc(n) local nn: nn:=convert(n, base, 10): add(nn[j], j=1..nops(nn)) end: a:=proc(n) if sd(sigma(n)^phi(n)) mod n = 0 then n else fi end: seq(a(n), n=1..2000); # Emeric Deutsch, Jul 25 2006
MATHEMATICA
Do[s = DivisorSigma[1, n]^EulerPhi[n]; k = Plus @@ IntegerDigits[s]; If[Mod[k, n] == 0, Print[n]], {n, 1, 10^4}]
Select[Range[100000], Divisible[Total[IntegerDigits[DivisorSigma[1, #]^ EulerPhi[ #]]], #]&] (* Harvey P. Dale, Jan 03 2012 *)
CROSSREFS
KEYWORD
base,more,nonn
AUTHOR
Ryan Propper, Aug 06 2005
EXTENSIONS
More terms from Emeric Deutsch, Jul 25 2006
One more term (a(19)) from Harvey P. Dale, Jan 03 2012
a(20)-a(24) from Lars Blomberg, Dec 02 2016
STATUS
approved