A053476 Smallest number m such that when A051953 is applied n times to m the result is neither a power of 2 nor 0.
9, 21, 42, 82, 130, 330, 450, 666, 1050, 1470, 1950, 2922, 4074, 5586, 7770, 11154, 15810, 22638, 30702, 42570, 53130, 68970, 107690, 159390, 206910, 289830, 395190, 610350, 823290, 1185570, 1522290, 2168250, 3011850, 4103490, 5364450
Offset: 1
Keywords
Examples
a(6)=330 and the iteration of A051953 applied to 330 gives sequence {330,250,150,110,70,46,24,16,8,4,2,1,0}. Six iterations result in the 6th term 24 which still is neither a power of 2 nor 0. For smaller numbers than 330 these 6 iterations yield a power of 2 or the fixed number 0.
Crossrefs
Cf. A051953, see also its iterates.
Formula
Applying cototient-function A051953 n+1 times to a(n), a power of 2 or 0 appears; a(n) is the smallest with this property.
Extensions
More terms from Jud McCranie, Jan 14 2000
Comments