login
A066367
The floor(p(n)/n)-perfect numbers, where p(n) denotes the n-th prime and f-perfect numbers for an arithmetical function f are defined in A066218.
0
5, 7, 11, 49, 169
OFFSET
1,1
LINKS
J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.
MATHEMATICA
f[x_] := Floor[Prime[x] / x]; Select[ Range[2, 10^5], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ] There do not seem to be any more terms. There are no terms between 170 and 10^5.
CROSSREFS
Cf. A066218.
Sequence in context: A106714 A106819 A045968 * A098036 A127269 A071781
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Dec 21 2001
STATUS
approved