login
A366795
a(n) = A344695(A005940(1+n)), where A344695(n) = gcd(psi(n), sigma(n)), and A005940 is the Doudna sequence.
3
1, 3, 4, 1, 6, 12, 1, 3, 8, 18, 24, 4, 1, 3, 4, 1, 12, 24, 32, 6, 48, 72, 6, 12, 1, 3, 4, 1, 6, 12, 1, 3, 14, 36, 48, 8, 72, 96, 8, 18, 96, 144, 192, 24, 8, 18, 24, 4, 1, 3, 4, 1, 6, 12, 1, 3, 8, 18, 24, 8, 1, 3, 4, 1, 18, 42, 56, 12, 84, 144, 12, 24, 112, 216, 288, 32, 12, 24, 32, 6, 168, 288, 384, 48, 576, 576
OFFSET
0,2
LINKS
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
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A344695(n) = gcd(sigma(n), A001615(n));
A366795(n) = A344695(A005940(1+n));
CROSSREFS
Cf. A005940, A344695, A366796 (rgs-transform).
Cf. also A346471, A366801, A366803.
Sequence in context: A132700 A193794 A281862 * A092261 A367991 A344695
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 26 2023
STATUS
approved