A174904 Smallest number m such that A174903(m) = n.

1, 6, 18, 12, 105, 24, 36, 48, 495, 60, 400, 192, 144, 120, 4656, 180, 1600, 240, 576, 1120, 10000, 360, 1296, 2240, 900, 960, 28920, 720, 25600, 840, 9216, 5600, 5184, 1260, 102400, 6160, 36864, 1680, 302500, 2880, 19600, 15360, 3600, 12320

Offset: 0

Author

Reinhard Zumkeller, Apr 01 2010

Keywords

• nonn

Comments

A174903(a(n)) = n and A174903(m) <> n for m < a(n).

Examples

			a(2)=18, A174903(18)=#{(2,3),(6,9)}=2;
a(3)=12, A174903(12)=#{(2,3),(3,4),(4,6)}=3;
a(4)=105, A174903(105)=#{(3,5),(5,7),(15,21),(21,35)}=4;
a(5)=24, A174903(24)=#{(2,3),(3,4),(4,6),(6,8),(8,12)}=5.
		

Programs

Haskell

import Data.List (elemIndex); import Data.Maybe (fromJust)
a174904 = (+ 1) . fromJust . (`elemIndex` map a174903 [1..])
-- Reinhard Zumkeller, Sep 29 2014