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A033941
Number of ways A002808(n) can be properly factored into 2 integers.
1
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
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
KEYWORD
nonn
AUTHOR
EXTENSIONS
Corrected by Robert Israel, Feb 15 2018
STATUS
approved