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A195864
Numbers n such that sigma(n) + tau(n) is a perfect number (A000396).
0
3, 14, 15, 168, 326, 5414, 33357341, 4324809536
OFFSET
1,1
COMMENTS
A002093(848) < a(9) <= 1155321467378283328. - Donovan Johnson, Nov 03 2011
MATHEMATICA
perfect = {6, 28, 496, 8128, 33550336, 8589869056, 137438691328}; Select[Range[10000], MemberQ[perfect, DivisorSigma[0, #] + DivisorSigma[1, #]] &] (* T. D. Noe, Nov 03 2011 *)
CROSSREFS
Cf. A007503 (sigma(n) + tau(n)).
Sequence in context: A037244 A016062 A009401 * A349767 A022890 A032920
KEYWORD
nonn
AUTHOR
Jeff Kruse, Oct 26 2011
EXTENSIONS
a(8) from Donovan Johnson, Nov 03 2011
STATUS
approved