A065743 Smallest number with exactly A025475(n) divisors.

1, 6, 24, 36, 120, 1296, 900, 840, 46656, 7560, 44100, 60466176, 810000, 83160, 2176782336, 2822400, 1081080, 2821109907456, 729000000, 101559956668416, 17297280, 131621703842267136, 1944810000, 341510400

Offset: 1

Author

Labos Elemer, Nov 15 2001

Keywords

• nonn

Comments

Note that 2^(n-1) has n divisors. - David Wasserman, Sep 09 2002

Links

• Amiram Eldar, Table of n, a(n) for n = 1..285

Crossrefs

Cf. A005179, A025475, A037992, A003680.

Programs

Mathematica

a = Table[ 0, {1024} ]; Do[ b = DivisorSigma[ 0, n]; If[ b < 1025 && a[[b]] == 0, a[[b]] = n], {n, 1, 10^8/2} ]; a[[ Select[ Range[2, 1024], !PrimeQ[ # ] && Mod[ #, # - EulerPhi[ # ]] == 0 & ] ]]

Formula

a(n) = A005179(A025475(n)).

Extensions

More terms from David Wasserman, Sep 09 2002