A324396 a(1) = 0; for n > 1, a(n) = A009194(A156552(n)).

0, 1, 1, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 3, 3, 1, 1, 4, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 6, 1, 1, 1, 1, 1, 2, 1, 1, 1, 12, 1, 2, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 3, 2, 1, 2, 3, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 10, 1, 1, 1, 6, 1, 1, 1, 12, 5, 6, 15, 1, 3, 3, 1, 2, 3, 4, 5, 1, 1, 2, 3, 1, 3, 1, 1, 6

Offset: 1

Author

Antti Karttunen, Mar 05 2019

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..4473
• Index entries for sequences computed from indices in prime factorization
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A009194, A156552, A323243, A323244, A324051, A324394, A324397, A324398.

Programs

PARI

A009194(n) = gcd(n, sigma(n));
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));
A324396(n) = if(1==n,0,A009194(A156552(n)));

Formula

a(1) = 0; for n > 1, a(n) = A009194(A156552(n)).

a(n) = gcd(A156552(n), A323243(n)).