A374031 a(n) = gcd(A276085(n), A328768(n)), where A276085 is the primorial base log-function, and A328768 is the first primorial based variant of arithmetic derivative.

0, 1, 2, 2, 6, 1, 30, 3, 4, 1, 210, 4, 2310, 1, 4, 4, 30030, 1, 510510, 4, 8, 1, 9699690, 1, 12, 1, 6, 4, 223092870, 1, 6469693230, 5, 4, 1, 12, 6, 200560490130, 1, 4, 9, 7420738134810, 1, 304250263527210, 4, 2, 1, 13082761331670030, 2, 60, 1, 4, 4, 614889782588491410, 1, 36, 3, 16, 1, 32589158477190044730, 2

Offset

1,3

Links

Table of n, a(n) for n=1..60.

Index entries for sequences related to primorial numbers

Prog

(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)); };
A328768(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]*A002110(primepi(f[i, 1])-1)/f[i, 1]));
A374031(n) = gcd(A276085(n), A328768(n));

Crossrefs

Cf. A002110, A276085, A328768, A374042 (positions of multiples of 3).

Sequence in context: A225975 A016529 A077894 * A053214 A077198 A046110

Adjacent sequences: A374028 A374029 A374030 * A374032 A374033 A374034

Keyword

nonn

Author

Antti Karttunen, Jun 26 2024

Status

approved