OFFSET
1,1
LINKS
J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172.
EXAMPLE
Let f(n) = floor(n/2). Then f(18) = 9 = 4+3+1+1+0 = f(9)+f(6)+f(3)+f(2)+f(1); so 18 is a term of the sequence.
MATHEMATICA
f[x_] := Floor[x/2]; Select[ Range[ 1, 10^5], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Joseph L. Pe, Dec 19 2001
EXTENSIONS
a(7)-a(15) from Amiram Eldar, Sep 26 2019
STATUS
approved