A111657 n-th composite number appears n-th prime times.

4, 4, 6, 6, 6, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 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, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15

Offset: 1

Author

Jonathan Vos Post, Aug 12 2005

Keywords

• easy
• nonn

References

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

Links

• L. Panaitopol, Some Properties of the Series of Composed Numbers, J. Inequalities in Pure and Applied Mathematics. 2(2): Article 38, 2000.
• J. B. Rosser and L. Schoenfeld, Approximate formulas for some functions of prime numbers, Illinois J. Math. 6: 64-94 (1962).
• Eric Weisstein's World of Mathematics, Composite Number.
• Eric Weisstein's World of Mathematics, Prime Number.

Crossrefs

Cf. A000040, A002808, A111653, A111654, A111655, A111656.

Formula

A002808(n) appears A000040(n) times.