A354216 Highly composite numbers (A002182) whose number of divisors is not a multiple of 3.

1, 2, 6, 24, 48, 120, 240, 840, 1680, 7560, 15120, 45360, 83160, 166320, 498960, 665280, 1081080, 2162160, 6486480, 8648640, 17297280, 36756720, 110270160, 147026880, 294053760, 698377680, 2095133040, 2793510720, 5587021440, 64250746560, 128501493120, 1606268664000

Offset

1,2

Comments

Is this sequence finite? (Note that any number divisible by p^2 but not by p^3 has a number of divisors divisible by 3.)

Among the first 10^5 terms of A002182, A002182(163) = 4381203794791824000 is the largest one that is a term of this sequence.

Links

Table of n, a(n) for n=1..32.

Example

48 is a highly composite number and it has 10 divisors and 10 is not a multiple of 3, so 48 is a term of this sequence.

Crossrefs

Cf. A002182, A002183.

Sequence in context: A092485 A113904 A099144 * A189851 A189563 A321613

Adjacent sequences: A354213 A354214 A354215 * A354217 A354218 A354219

Keyword

nonn

Author

J. Lowell, May 19 2022

Extensions

More terms from Amiram Eldar, May 19 2022

Status

approved