A092801 Standard deviation (rounded) of composites below 10^n.

2, 28, 285, 2873, 28795, 288244, 2883807, 28846206, 288514821, 2885502969, 28857521613, 288593332699, 2886069270370

Offset: 1

Author

Enoch Haga, Mar 06 2004

Keywords

• more
• nonn

Comments

As with the primes in A091716, each succeeding term seems a close multiple of that preceding.

Exact values: a(8)=sqrt(1055690147582754761176900206278/1268700426680407), a(9)=sqrt(2343463734895394416636292841043365/28152824997414728), a(10)=sqrt(758560349177461014920842710257059832362/91106022529587615169). [From Sean A. Irvine, Apr 07 2010]

Exact values from Sean A. Irvine are population standard deviations. - Hiroaki Yamanouchi, Sep 23 2014

Examples

			a(3) = 285 because this is the computed and rounded sample standard deviation of the composites below 10^3.
		

References

• John E. Freund, Modern elementary statistics, 5th ed. (Prentice-Hall, 1979), pp. 42-47

Crossrefs

Cf. A092802, A091716.

Extensions

Corrected and extended by Sean A. Irvine, Apr 07 2010

a(8) corrected and a(11)-a(13) from Hiroaki Yamanouchi, Sep 23 2014