

A111655


nth composite number appears nth 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, SpringerVerlag, 1976, page 2.
J. B. Rosser and L. Schoenfeld, Approximate formulas for some functions of prime numbers, Illinois J. Math. 6: 6494 (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



