OFFSET
1,1
COMMENTS
The slowest increasing sequence of semiprimes with coprime neighbor terms.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
gcd(a(n-1), a(n)) = 1.
MAPLE
A[1]:= 4: t:= 4: count:= 1:
for x from 5 while count < 100 do
if igcd(x, t) = 1 then
if numtheory:-bigomega(x)=2 then
count:= count+1;
A[count]:= x;
t:= x;
fi
fi
od:
seq(A[i], i=1..100); # Robert Israel, Jun 11 2023
PROG
(PARI) lista(nn) = {my(vsp = select((x->(bigomega(x) == 2)), vector(nn, k, k)), i = 1, last); while (i <= #vsp, print1(vsp[i], ", "); last = vsp[i]; while(gcd(vsp[i], last) != 1, i++; if (i>#vsp, break)); ); } \\ Michel Marcus, Jun 25 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 30 2007
STATUS
approved