A121858 Smallest odd number having prime(n) divisors, where prime(n) is the n-th prime=A000040(n).

3, 9, 81, 729, 59049, 531441, 43046721, 387420489, 31381059609, 22876792454961, 205891132094649, 150094635296999121, 12157665459056928801, 109418989131512359209, 8862938119652501095929, 6461081889226673298932241

Offset: 1

Author

Lekraj Beedassy, Aug 30 2006

Keywords

• nonn

Comments

a(n) is also the smallest number k with the property that the symmetric representation of sigma(k) has prime(n) subparts. - Omar E. Pol, Oct 08 2022

Crossrefs

Cf. A006093, A061286.

Cf. A000040, A038546, A237593, A279387.

Programs

Mathematica

3^(Prime[Range[20]]-1) (* Harvey P. Dale, Mar 19 2013 *)

Formula

a(n) = 3^(prime(n)-1) = 3^A006093(n).

a(n) = A038547(A000040(n)). - Omar E. Pol, Oct 08 2022