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A107286
a(0) = 0; for n>0, minimal prime factor of n, or 1 if n is 1 or a prime.
6
0, 1, 1, 1, 2, 1, 2, 1, 2, 3, 2, 1, 2, 1, 2, 3, 2, 1, 2, 1, 2, 3, 2, 1, 2, 5, 2, 3, 2, 1, 2, 1, 2, 3, 2, 5, 2, 1, 2, 3, 2, 1, 2, 1, 2, 3, 2, 1, 2, 7, 2, 3, 2, 1, 2, 5, 2, 3, 2, 1, 2, 1, 2, 3, 2, 5, 2, 1, 2, 3, 2, 1, 2, 1, 2, 3, 2, 7, 2, 1, 2, 3, 2, 1, 2, 5, 2, 3, 2, 1, 2, 7, 2, 3, 2, 5, 2, 1, 2, 3
OFFSET
0,5
LINKS
PROG
(PARI) a(n) = if (n==0, 0, if (n==1, 1, if (isprime(n), 1, factor(n)[1, 1]))) \\ Michel Marcus, Jun 03 2013
CROSSREFS
Cf. A020639.
Sequence in context: A082067 A082061 A327979 * A339791 A087039 A102096
KEYWORD
nonn,look
AUTHOR
Giovanni Teofilatto, May 20 2005
STATUS
approved