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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: A179414 A139324 * A175961 A113646 A106325 A159835

Adjacent sequences:  A111652 A111653 A111654 * A111656 A111657 A111658

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Aug 12 2005

STATUS

approved

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Last modified November 19 10:44 EST 2017. Contains 294936 sequences.