OFFSET
0,7
COMMENTS
Number of even numbers encountered before zero is reached when starting from k = n and repeatedly applying the map that replaces k by k - d(k), where d(k) is the number of divisors of k (A000005). This count includes n itself if it is even, but excludes the zero.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..10080
FORMULA
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 03 2015
STATUS
approved