A066245 Floor(|x*sin(x)|)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218.

3, 6, 10, 34, 50, 91, 222, 364, 1485, 6640, 18579, 775698, 1035507, 1706366, 46388515, 75714802

Offset: 1

Author

Joseph L. Pe, Dec 19 2001

Keywords

• nonn
• more

Examples

			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.
		

Links

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

Crossrefs

Cf. A066218.

Programs

Mathematica

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

Extensions

a(11)-a(16) from Amiram Eldar, Sep 26 2019