

A111653


nth composite number appears n times.


4



4, 6, 6, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 16, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21
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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..73.
Eric Weisstein's World of Mathematics, Composite Number."


FORMULA

A002808(n) appears n times.


CROSSREFS

Cf. A002808, A111654, A111655.
Sequence in context: A254275 A074672 A070259 * A228363 A334289 A173395
Adjacent sequences: A111650 A111651 A111652 * A111654 A111655 A111656


KEYWORD

easy,nonn


AUTHOR

Jonathan Vos Post, Aug 12 2005


STATUS

approved



