

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), 3637.


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. A038623A038627, A102281, A087237.
Sequence in context: A079770 A079771 A258438 * 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



