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A066245 Floor(|x sin(x)|)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218. 0
3, 6, 10, 34, 50, 91, 222, 364, 1485, 6640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

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

EXAMPLE

Let f(n) = floor(|x sin(x)|). Then f(6) = 1 = 0+1+0 = f(3)+f(2)+f(1); so 6 is a term of the sequence.

MATHEMATICA

f[x_] := Floor[Abs[x*Sin[x]]]; Select[ Range[2, 10^4], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]

CROSSREFS

Sequence in context: A001465 A094276 A151376 * A068821 A062100 A262242

Adjacent sequences:  A066242 A066243 A066244 * A066246 A066247 A066248

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Dec 19 2001

STATUS

approved

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Last modified November 14 03:52 EST 2018. Contains 317159 sequences. (Running on oeis4.)