A128558 a(n) = the number of positive divisors of (n!/A128557(n)!).

1, 2, 4, 6, 6, 8, 8, 8, 12, 12, 24, 12, 24, 32, 16, 20, 40, 36, 24, 48, 24, 64, 32, 40, 48, 60, 48, 64, 48, 64, 32, 56, 48, 56, 64, 36, 72, 48, 128, 80, 64, 80, 160, 64, 72, 96, 48, 48, 60, 108, 72, 96, 192, 64, 64, 160, 128, 80, 160, 64, 128, 64, 256, 96, 168, 128, 256, 256

Offset

1,2

Comments

a(n) is >= n, for each positive integer n.

Links

Table of n, a(n) for n=1..68.

Maple

A128557 := proc(n) local A, k: A:={}: for k from 1 to n do if numtheory[tau](n!/k!)>=n then A:=A union {k} else A:=A fi od: A[nops(A)]; end: A128558 := proc(n) numtheory[tau]( n!/A128557(n)!) ; end: seq(A128558(n), n=1..80) ; # R. J. Mathar, Oct 09 2007

Crossrefs

Cf. A128557.

Sequence in context: A349787 A161655 A092517 * A090346 A267460 A092989

Adjacent sequences: A128555 A128556 A128557 * A128559 A128560 A128561

Keyword

nonn

Author

Leroy Quet, Mar 10 2007

Extensions

More terms from R. J. Mathar, Oct 09 2007

Status

approved