A340147 a(n) = A247074(A003961(n)).

1, 1, 1, 3, 1, 2, 1, 9, 5, 3, 1, 3, 1, 5, 6, 27, 1, 10, 1, 9, 10, 6, 1, 18, 7, 8, 25, 15, 1, 3, 1, 81, 3, 9, 15, 15, 1, 11, 4, 27, 1, 5, 1, 9, 10, 14, 1, 27, 11, 21, 18, 6, 1, 50, 2, 45, 22, 15, 1, 18, 1, 18, 50, 243, 24, 12, 1, 27, 7, 3, 1, 90, 1, 20, 21, 33, 30, 16, 1, 81, 125, 21, 1, 30, 3, 23, 30, 54, 1, 15, 40, 21

Offset

1,4

Comments

Prime shifted analog of A247074.

Each term a(n) is a divisor of A340072(n).

Links

Antti Karttunen, Table of n, a(n) for n = 1..8191

Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Index entries for sequences computed from indices in prime factorization

Formula

a(n) = A247074(A003961(n)).

a(n) = A003972(n) / A340148(n).

Prog

(PARI)
A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A247074(n) = { my(f=factor(n)); eulerphi(f)/prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); }; \\ From A247074
A340147(n) = A247074(A003961(n));

Crossrefs

Cf. A003961, A003972, A247074, A340072, A340148, A340149 (odd part).

Sequence in context: A349380 A351425 A249580 * A011086 A321889 A321751

Adjacent sequences: A340144 A340145 A340146 * A340148 A340149 A340150

Keyword

nonn

Author

Antti Karttunen, Dec 30 2020

Status

approved