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A038626 Smallest value of pi(x) having n*pi(x) = x. 6
1, 9, 24, 66, 168, 437, 1051, 2614, 6454, 15927, 40071, 100346, 251706, 637197, 1617172, 4124436, 10553399, 27066969, 69709679, 179992838, 465769802, 1208198523, 3140421715, 8179002095, 21338685402 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

COMMENTS

Golomb shows that solutions exist for each n>1.

a(n) is the smallest natural number m such that m = pi(n*m). For all known terms of this sequence the relation, " 2.4*a(n) < a(n+1) < 2.7*a(n) + 7 " is true. A038627(n) gives number of natural solutions of the equation m = pi(n*m). - Farideh Firoozbakht, Jan 09 2005

REFERENCES

S. W. Golomb, On the Ratio of N to pi(N), American Mathematical Monthly, 69 (1962), 36-37.

LINKS

Table of n, a(n) for n=2..26.

Eric Weisstein's World of Mathematics, Prime Counting Function.

EXAMPLE

pi(3059) = 437 and 3059/437 = 7, so a(7)=437

CROSSREFS

Cf. A038623-A038627, A102281, A087237.

Sequence in context: A022787 A079770 A079771 * A195970 A223372 A180334

Adjacent sequences:  A038623 A038624 A038625 * A038627 A038628 A038629

KEYWORD

nonn,more

AUTHOR

Jud McCranie

EXTENSIONS

One more term from Farideh Firoozbakht, Jan 09 2005

Edited by N. J. A. Sloane at the suggestion of Chris Caldwell, Apr 08 2008

a(25), a(26) from Max Alekseyev, Jul 18 2011

STATUS

approved

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Last modified October 25 23:29 EDT 2014. Contains 248566 sequences.