A033941 Number of ways A002808(n) can be properly factored into 2 integers.

1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 3, 1, 1, 1, 2, 3, 2, 1, 1, 1, 4, 1, 1, 3, 3, 2, 2, 1, 4, 1, 2, 1, 2, 3, 1, 3, 1, 1, 5, 1, 2, 3, 1, 3, 2, 1, 3, 5, 1, 2, 2, 1, 3, 4, 2, 1, 5, 1, 1, 1, 3, 5, 1, 2, 1, 1, 1, 5, 2, 2, 4, 3, 3, 3, 1, 5, 3, 1, 4, 3, 1, 2, 2, 1, 1, 7, 1, 1, 1, 2, 1, 5, 3, 1, 3, 5, 1, 1, 3, 3, 3, 5

Offset

1,6

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

f:= proc(t) if not isprime(t) then (numtheory:-tau(t) +`if`(issqr(t), 1, 0))/2 - 1 fi end proc:
map(f, [$4..1000]); # Robert Israel, Feb 15 2018

Prog

(PARI) f(n) = (numdiv(n) + issquare(n))/2 - 1;
lista(nn) = forcomposite(n=1, nn, print1(f(n), ", ")) \\ Michel Marcus, Feb 16 2018

Crossrefs

Sequence in context: A123245 A262611 A110535 * A053256 A336498 A102418

Adjacent sequences: A033938 A033939 A033940 * A033942 A033943 A033944

Keyword

nonn

Author

Jeff Burch

Extensions

Corrected by Robert Israel, Feb 15 2018

Status

approved