A379491 Multiperfect numbers k for which gcd(k,A003961(k))*gcd(sigma(k),A276086(k)) is equal to gcd(k,A276086(k))*gcd(sigma(k),A003961(k)), where A003961(n) is fully multiplicative with a(prime(i)) = prime(i+1), and A276086 is the primorial base exp-function.

1, 6, 28, 496, 8128, 30240, 32760, 2178540, 23569920, 33550336, 45532800, 142990848, 459818240, 1379454720, 8589869056, 43861478400, 51001180160, 66433720320, 137438691328, 153003540480, 403031236608, 704575228896, 181742883469056, 6088728021160320, 14942123276641920, 20158185857531904, 275502900594021408, 622286506811515392

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..993

Index entries for sequences related to prime indices in the factorization of n.

Index entries for sequences related to primorial base.

Index entries for sequences related to sigma(n).

Prog

(PARI) isA379491(n) = (!(sigma(n)%n) && A379485(n));

Crossrefs

Intersection of A007691 and A379486.

Cf. A000203, A003961, A276086, A322361, A324198, A324644, A342671, A379485, A379487, A379488, A379492 (complement in A007691).

Subsequences: A323653 (conjectured), A336702 (apart from any hypothetical odd terms > 1).

Sequence in context: A345004 A370789 A351440 * A325637 A336702 A325654

Adjacent sequences: A379488 A379489 A379490 * A379492 A379493 A379494

Keyword

nonn

Author

Antti Karttunen, Jan 02 2025

Status

approved