A177962 Number of distinct transpositions of prime factors of n-th composite number.

1, 2, 1, 1, 2, 3, 2, 2, 1, 3, 3, 2, 2, 4, 1, 2, 1, 3, 6, 1, 2, 2, 2, 6, 2, 2, 4, 6, 3, 3, 2, 5, 1, 3, 2, 3, 4, 2, 4, 2, 2, 12, 2, 3, 1, 2, 6, 3, 2, 6, 10, 2, 3, 3, 2, 6, 5, 1, 2, 12, 2, 2, 2, 4, 12, 2, 3, 2, 2, 2, 6, 3, 3, 6, 6, 4, 6, 2, 10, 6, 2, 5, 6, 2, 3, 3, 2, 2, 20, 1, 2, 2, 3, 1, 12, 1, 2, 6, 12, 2, 2

Offset

1,2

Links

Table of n, a(n) for n=1..101.

Formula

a(n) = A008480(A002808(n)). - R. J. Mathar, May 28 2010

Example

a(1)=1 because 1st composite = 4 and (2*2)=1.
a(2)=2 because 2nd composite = 6 and (2*3 or 3*2) = 2.

Maple

A177962 := proc(n) local c; c := A002808(n) ; a := (numtheory[bigomega](c))! ; for p in ifactors(c)[2] do a := a/ op(2, p)! ; end do: a ; end proc:
seq(A177962(n), n=1..120) ; # R. J. Mathar, May 28 2010

Crossrefs

Cf. A002808, A177687.

Sequence in context: A091598 A144021 A334591 * A246552 A161091 A027347

Adjacent sequences: A177959 A177960 A177961 * A177963 A177964 A177965

Keyword

nonn

Author

Juri-Stepan Gerasimov, May 16 2010

Extensions

Entries checked by R. J. Mathar, May 28 2010

Status

approved