A340074 a(n) = gcd(A003961(n)-1, A339904(n)).

1, 1, 1, 1, 3, 1, 5, 1, 1, 1, 3, 1, 1, 1, 1, 1, 9, 1, 11, 1, 1, 1, 7, 1, 3, 1, 1, 1, 15, 1, 9, 1, 1, 1, 1, 1, 5, 1, 1, 1, 21, 1, 23, 1, 3, 1, 13, 1, 5, 1, 1, 1, 29, 1, 9, 1, 1, 1, 15, 1, 33, 1, 1, 1, 1, 1, 35, 1, 1, 5, 9, 1, 39, 1, 1, 1, 1, 1, 41, 1, 1, 1, 11, 1, 3, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 25, 1, 3, 1, 51, 1, 53, 1, 3

Offset

1,5

Comments

Odd part of A340071(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) = gcd(A003961(n)-1, A339904(n)).

a(n) = A000265(A340071(n)).

a(n) = A339904(n) / A340075(n).

Prog

(PARI)
A000265(n) = (n>>valuation(n, 2));
A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A339904(n) = A000265(eulerphi(A003961(n)));
A340074(n) = gcd(A003961(n)-1, A339904(n));

Crossrefs

Cf. A000265, A003961, A339904, A340071, A340075.

Sequence in context: A176907 A143069 A010286 * A344592 A176801 A339903

Adjacent sequences: A340071 A340072 A340073 * A340075 A340076 A340077

Keyword

nonn

Author

Antti Karttunen, Dec 29 2020

Status

approved