login
A346471
a(n) = A344695(A276086(n)), where A344695(x) = gcd(psi(x), sigma(x)), and A276086 gives the prime product form of primorial base expansion of n.
9
1, 3, 4, 12, 1, 3, 6, 18, 24, 72, 6, 18, 1, 3, 4, 12, 1, 3, 6, 18, 24, 72, 12, 36, 1, 3, 4, 12, 1, 3, 8, 24, 32, 96, 8, 24, 48, 144, 192, 576, 48, 144, 8, 24, 32, 96, 8, 24, 48, 144, 192, 576, 96, 288, 8, 24, 32, 96, 8, 24, 1, 3, 4, 12, 3, 9, 6, 18, 24, 72, 18, 54, 3, 9, 12, 36, 3, 9, 12, 36, 48, 144, 36, 108, 3, 9, 12, 36
OFFSET
0,2
FORMULA
a(n) = A344695(A276086(n)) = gcd(A324653(n), A346470(n)).
PROG
(PARI)
A001615(n) = if(1==n, n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A344695(n) = gcd(sigma(n), A001615(n));
CROSSREFS
KEYWORD
nonn,base,look
AUTHOR
Antti Karttunen, Jul 21 2021
STATUS
approved