A324645 - OEIS

%I #6 Mar 11 2019 20:47:48

%S 1,1,2,3,2,1,2,1,3,1,2,1,2,1,2,5,2,1,2,3,2,1,2,1,1,1,2,3,2,1,2,3,2,1,

%T 2,1,2,1,2,1,2,1,2,3,6,1,2,5,1,3,2,3,2,1,2,1,2,1,2,1,2,1,6,7,2,1,2,3,

%U 2,1,2,1,2,1,6,3,2,1,2,5,5,1,2,1,2,1,2,1,2,1,2,3,2,1,2,1,2,3,6,9,2,1,2,1,2

%N a(n) = gcd(d(n), A276086(n)), where d(n) gives the number of divisors (A000005).

%H Antti Karttunen, <a href="/A324645/b324645.txt">Table of n, a(n) for n = 1..30030</a>

%F a(n) = gcd(A000005(n), A276086(n)).

%o (PARI)

%o 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; };

%o A324645(n) = gcd(numdiv(n),A276086(n));

%Y Cf. A000005, A009191, A276086, A324644.

%K nonn

%O 1,3

%A _Antti Karttunen_, Mar 11 2019