A102281 a(n) is the largest number m such that m = pi(n*m).

4, 11, 30, 72, 189, 442, 1059, 2700, 6472, 15927, 40121, 100363, 251761, 637340, 1617174, 4124705, 10553853, 27067277, 69709965, 179993173, 465769838, 1208198861, 3140421934, 8179002208, 21338685406, 55762149115, 145935689393

Offset

2,1

Comments

All known terms of this sequence satisfy the relation 2.4*a(n) - 12 < a(n+1) < 2.7*a(n) + 1 is true.

a(n) is the largest number m such that floor(prime(m)/m)=n-1. - Farideh Firoozbakht, Sep 13 2005

Links

Giovanni Resta, Table of n, a(n) for n = 2..50

Example

3140421934 = pi(24*3140421934) and 3140421934 is the largest number with this property, so a(24) = 3140421934.

Crossrefs

Cf. A038625, A038626, A038627, A087237.

Sequence in context: A308082 A099065 A296262 * A269083 A026583 A339739

Adjacent sequences: A102278 A102279 A102280 * A102282 A102283 A102284

Keyword

nonn

Author

Farideh Firoozbakht, Jan 09 2005; extended Sep 13 2005

Extensions

a(24) corrected by Max Alekseyev, Jul 18 2011

a(29)-a(50) obtained from the A038625 values computed by Jan Büthe. - Giovanni Resta, Aug 31 2018

Status

approved