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A066361
The floor(n^(.9999))-perfect numbers, where f-perfect numbers for an arithmetical function f is defined in A066218.
0
2, 18, 17816, 116624
OFFSET
1,1
COMMENTS
Despite the closeness of f(n) = floor(n^(.9999)) to floor(n) (which generates the usual perfect numbers), the perfect numbers generated by these functions are quite different.
LINKS
J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.
MATHEMATICA
f[x_] := Floor[x^(.9999)]; Select[ Range[2, 10^6], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]
CROSSREFS
Cf. A066218.
Sequence in context: A208056 A276092 A191554 * A120929 A349886 A007184
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Dec 20 2001
STATUS
approved