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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A111655 n-th composite number appears n-th composite number times. 5
4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 2.

J. B. Rosser and L. Schoenfeld, Approximate formulas for some functions of prime numbers, Illinois J. Math. 6: 64-94 (1962).

L. Panaitopol, Some Properties of the Series of Composed [Composite] Numbers, J. Inequalities in Pure and Applied Mathematics. 2(2): Article 38, 2000.

LINKS

Table of n, a(n) for n=1..78.

Eric Weisstein's World of Mathematics, Composite Number."

FORMULA

A002808(n) appears A002808(n) times.

CROSSREFS

Cf. A002808, A111653, A111654.

Sequence in context: A140744 A179414 A139324 * A175961 A113646 A106325

Adjacent sequences:  A111652 A111653 A111654 * A111656 A111657 A111658

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Aug 12 2005

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 December 7 12:17 EST 2021. Contains 349581 sequences. (Running on oeis4.)