OFFSET
0,12
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..20000
PROG
(PARI)
f = numdiv;
a(n) = f(f(n+1)) - f(f(n));
concat([1], vector(166, n, a(n))) \\ Joerg Arndt, Jul 06 2013
(PARI)
f(n) = if(!n, n, numdiv(n));
A111407(n) = f(f(n+1)) - f(f(n)); \\ Antti Karttunen, Oct 07 2017
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 12 2005
EXTENSIONS
Description clarified by Antti Karttunen, Oct 07 2017
STATUS
approved