A066367 The floor(prime(n)/n)-perfect numbers, where prime(n) denotes the n-th prime and f-perfect numbers for an arithmetical function f are defined in A066218.

5, 7, 11, 49, 169

Offset: 1

Author

Joseph L. Pe, Dec 21 2001

Keywords

• nonn
• more

Comments

There do not seem to be any more terms. There are no terms between 170 and 10^5.

Links

• J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.

Crossrefs

Cf. A038605, A066218.

Programs

Mathematica

f[x_] := Floor[Prime[x] / x]; Select[ Range[2, 10^3], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]