A061218 Least number whose number of divisors is n-th term from A014613 (numbers of form p*q*r*s, products of exactly 4 primes, counted with multiplicity).

120, 360, 1260, 1680, 6300, 6720, 5040, 44100, 20160, 107520, 25200, 45360, 430080, 100800, 322560, 176400, 6881280, 181440, 226800, 27525120, 1290240, 440401920, 705600, 1632960, 1612800, 20643840, 907200, 2903040, 1587600, 82575360, 28185722880, 6451200, 112742891520

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Formula

a(n) = A005179(A014613(n)).

Example

p*q*r*s = 210 is the 27th term in A014613; the smallest number with 210 divisors is 907200 = 2*2*2*2*2*2*3*3*3*3*5*5*7.

Crossrefs

Cf. A000005, A005179, A014613, A061148, A061149, A061299.

Sequence in context: A052768 A242845 A234915 * A321841 A052778 A354625

Adjacent sequences: A061215 A061216 A061217 * A061219 A061220 A061221

Keyword

nonn

Author

Labos Elemer, Jun 06 2001

Extensions

Corrected and extended by Michel Marcus, Sep 05 2017

Status

approved