A327168 Number of common divisors of n and A276086(n), with a(0) = 1.

1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 2, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 2, 1, 2, 1, 1, 4, 1, 1, 1, 2, 3, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 2, 4, 1, 1, 1, 1, 6, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 3, 2, 2, 1, 1, 1, 1, 8

Offset

0,4

Links

Antti Karttunen, Table of n, a(n) for n = 0..16383

Antti Karttunen, Data supplement: n, a(n) computed for n = 0..65537

Index entries for sequences related to primorial base

Formula

a(n) = A000005(A324198(n)).

a(n) = 1+A001222(A327167(n)) for n >= 1.

Prog

(PARI)
A276086(n) = { my(i=0, m=1, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m*=(prime(i)^((n%nextpr)/pr)); n-=(n%nextpr)); pr=nextpr); m; };
A327168(n) = numdiv(gcd(n, A276086(n)));

Crossrefs

Cf. A000005, A001222, A276086, A324198, A327167.

Cf. also A323878.

Sequence in context: A279060 A324119 A083382 * A329037 A279794 A025900

Adjacent sequences: A327165 A327166 A327167 * A327169 A327170 A327171

Keyword

nonn

Author

Antti Karttunen, Sep 19 2019

Status

approved