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A069457 Lowest primes in twin packs. 3
3, 101, 137, 179, 419, 809, 1019, 1049, 1481, 1871, 1931, 2081, 2111, 2969, 3251, 3359, 3461, 4217, 4259, 5009, 5651, 5867, 6689, 6761, 6947, 7331, 7547, 8219, 8969, 9419, 10007, 11057, 11159, 11699, 12239, 13001, 13709, 13997 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
A twin pack of primes contains 2 or more pairs of twin primes, between which pairs there are no other primes. 137 is in the sequence because 137,139 are prime and the next primes are 149,151.
MAPLE
state:= 0: p:=13: Res:= 3: count:= 1;
while count < 100 do
q:= nextprime(p);
if state = 0 then
if q = p+2 then state:= 1; r:= p; p:= nextprime(q);
else p:= q
fi;
elif state = 1 then
if q = p+2 then
count:= count+1; Res:= Res, r; state:= 2; p:= nextprime(q);
else p:= q; state:= 0
fi
else
if q = p+2 then
p:= nextprime(q);
else p:= q; state:= 0
fi
fi
od:
Res; # Robert Israel, Jan 13 2020
CROSSREFS
Sequence in context: A128296 A037114 A336437 * A142416 A110625 A108220
KEYWORD
nonn
AUTHOR
Neil Fernandez, Mar 23 2002
STATUS
approved

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Last modified May 25 10:45 EDT 2024. Contains 372788 sequences. (Running on oeis4.)