OFFSET
0,1
COMMENTS
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..1001
FORMULA
a(0) = 12, a(n) = A064216(a(n-1)).
EXAMPLE
Start with a(0) = 12; then after each new term is obtained by doubling the previous term, from which one is subtracted, after which each prime factor is replaced with the previous prime:
12 -> ((2*12)-1) = 23 = p_9, and p_8 = 19, thus a(1) = 19.
19 -> ((2*19)-1) = 37 = p_12, and p_11 = 31, thus a(2) = 31.
31 -> ((2*31)-1) = 61 = p_18, and p_17 = 59, thus a(3) = 59.
59 -> ((2*59)-1) = 117 = 3*3*13 = p_2 * p_2 * p_6, and p_1 * p_1 * p_5 = 2*2*11 = 44, thus a(4) = 44.
PROG
CROSSREFS
A246342 gives the terms of the same cycle when going to the opposite direction from 12.
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 24 2014
STATUS
approved