OFFSET
0,1
COMMENTS
Iterates of the map k -> k', starting from k=128, where k' stands for the arithmetic derivative, A003415.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..89
FORMULA
a(0) = 128, and for n > 0, a(n) = A003415(a(n-1)).
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
(PARI)
up_to = 89;
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A369638list(up_to) = { my(v=vector(up_to)); v[1] = 128;
for(i=2, up_to, print1(i, ", "); v[i] = A003415(v[i-1])); (v); };
v369638 = A369638list(1+up_to);
A369638(n) = v369638[1+n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 04 2024
STATUS
approved