1,1

Conjecture: all a(n) are prime numbers.

This conjecture is false: a(643) = 6 is not prime. - Alois P. Heinz, Oct 23 2013

Table of n, a(n) for n=1..83.

a(3) cannot be 2 because the third highly composite number, 4, when multiplied by 2, yields 8, which is not a highly composite number.

Cf. A002182.

Sequence in context: A329612 A305980 A329601 * A089132 A107259 A121041

Adjacent sequences: A230575 A230576 A230577 * A230579 A230580 A230581

nonn

J. Lowell, Oct 23 2013

More terms from Alois P. Heinz, Oct 23 2013

approved