A351623 Numbers k where 3k sets a record for the number of divisors of multiples of 3.

1, 2, 4, 8, 12, 16, 20, 40, 60, 80, 120, 240, 280, 420, 560, 840, 1680, 2520, 3360, 5040, 6720, 8400, 9240, 15120, 16800, 18480, 27720, 36960, 55440, 73920, 92400, 110880, 166320, 184800, 221760, 240240, 360360, 480480, 720720, 960960, 1201200, 1441440, 2162160, 2402400

Offset: 1

Author

J. Lowell, May 04 2022

Keywords

• nonn

Comments

This sequence may be useful for understanding A352797.

Examples

			6 is not in the sequence because 3*6=18 and 3*4=12 each have 6 divisors.
8 is in the sequence because 3*8=24 sets a record for the number of divisors of multiples of 3.
		

Crossrefs

Cf. A002182, A352797.

Programs

PARI

lista(nn) = {my(m=0, nm); for (n=1, nn, if ((nm=numdiv(3*n)) > m, m = nm; print1(n, ", ")););} \\ Michel Marcus, May 04 2022

Formula

For n > 1, a(n) = A002182(n+2)/3.

Extensions

More terms from Michel Marcus, May 04 2022