A351254 a(n) = A276085(gcd(n, A276086(n))).

0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 8, 0, 0, 0, 0, 6, 2, 0, 0, 0, 12, 0, 2, 0, 0, 0, 0, 0, 2, 0, 30, 0, 0, 0, 2, 6, 0, 30, 0, 0, 8, 0, 0, 0, 30, 12, 2, 0, 0, 0, 6, 30, 2, 0, 0, 0, 0, 0, 32, 0, 0, 0, 0, 0, 2, 36, 0, 0, 0, 0, 14, 0, 30, 0, 0, 6, 2, 0, 0, 30, 6, 0, 2, 0, 0, 0, 30, 0, 2, 0, 0, 0, 0, 60, 2, 6

Offset: 0

Author

Antti Karttunen, Feb 05 2022

Keywords

• nonn
• easy

Links

• Antti Karttunen, Table of n, a(n) for n = 0..65537

Crossrefs

Cf. A276085, A276086, A324198, A351253.

Cf. also A351234.

Cf. A324583 (positions of the rest of zeros after a(0)=0).

Programs

PARI

A002110(n) = prod(i=1,n,prime(i));
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
A324198(n) = { my(m=1, p=2, orgn=n); while(n, m *= (p^min(n%p, valuation(orgn, p))); n = n\p; p = nextprime(1+p)); (m); };
A351254(n) = A276085(A324198(n));

Formula

a(n) = A276085(A324198(n)) = A276085(gcd(n, A276086(n))).

a(n) = n - A351253(n).