login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A161166 Decimal expansion of a constant in the linear term in the growth rate of unitary squarefree divisors. 6
7, 4, 8, 3, 7, 2, 3, 3, 3, 4, 2, 9, 6, 7, 4 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Other constituents of the linear term are in A065463, A073002, A001620 and A059956.

REFERENCES

D. Suryanarayana and V. Siva Rama Prasad, The number of k-ary, k+1-free divisors of an integer, J. Reine Angew. Math. 276 (1975) 15-35.

LINKS

Table of n, a(n) for n=0..14.

Steven R. Finch, Unitarism and Infinitarism, February 25, 2004. [Cached copy, with permission of the author]

FORMULA

Equals sum_{primes p} (2p+1)*log(p)/((p+1)(p^2+p-1)) = sum_p log(p)*[2/(p^2-1)-3/p^3-1)+4/(p^4-1)-10/(p^5-1)....] where the terms accumulate; this is essentially the logarithmic derivative of the Riemann zeta function at s=2, 3, 4,...

CROSSREFS

Sequence in context: A021576 A222183 A010509 * A199060 A330596 A296427

Adjacent sequences:  A161163 A161164 A161165 * A161167 A161168 A161169

KEYWORD

cons,nonn

AUTHOR

R. J. Mathar, Jun 04 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 1 20:49 EDT 2020. Contains 334765 sequences. (Running on oeis4.)