1,1

a(20) >= 150. - Max Alekseyev, Aug 26 2021

Table of n, a(n) for n=1..19.

Hisanori Mishima, Factorizations of many number sequences

a(1) = 9 so A005165(9) = 326981 = 79 * 4139 is a semiprime.

Cf. A001272, A005165.

Sequence in context: A202707 A031078 A216292 * A071217 A064930 A158607

Adjacent sequences: A250292 A250293 A250294 * A250296 A250297 A250298

nonn

Eric Chen, Dec 24 2014

a(18)-a(19) from Max Alekseyev, Aug 26 2021

approved