term% cat index.txt FACTOR(1) General Commands Manual FACTOR(1)
NAME
factor, lfactor, qfactor, primes - factor a number, generate large
primes
SYNOPSIS
factor [ number ]
lfactor
qfactor
primes [ start [ finish ] ]
DESCRIPTION
Factor prints number and its prime factors, each repated the proper
number of times. The number must be positive and less than 2**56
(about 7.2e16)
If no number is given, factor reads a stream of numbers from the stan‐
dard input and factors them. It exits on any input not a positive in‐
teger.
Maximum time to factor is proportional to sqrt(n) and occurs when n is
prime or the square of a prime.
Lfactor reads one number from the standard input and factors it.
Worst-case running time is proportional to n**(1/5); it beats factor
for hard 12-digit problems and is workable to around n=10**30. Qfactor
reads one number from the standard input and factors it. It is almost
always better than lfactor , and will factor numbers up to about 40
digits.
Primes prints the prime numbers ranging from start to finish, where
start and finish are positive numbers less than 2**56. If finish is
missing, primes prints without end; if start is missing, it reads the
starting number from the standard input.
DIAGNOSTICS
‘Ouch.' for input out of range or for garbage input.
BUGS
Lfactor makes mysterious progress reports on its arcane inner workings.
Qfactor does too.
FACTOR(1)