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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..5.

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

Adjacent sequences:  A066364 A066365 A066366 * A066368 A066369 A066370

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Dec 21 2001

STATUS

approved

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Last modified September 21 08:38 EDT 2020. Contains 337268 sequences. (Running on oeis4.)