|
|
A340225
|
|
Primes p such that 2*p+q and 2*p+r are prime, where q and r are the next two primes after p.
|
|
2
|
|
|
3, 19, 241, 439, 577, 743, 787, 983, 1549, 1637, 1699, 1879, 2273, 2843, 3929, 4157, 4201, 4583, 5669, 5791, 6301, 6659, 7559, 11887, 12163, 12517, 12889, 13007, 13049, 13219, 13759, 13879, 14149, 15139, 18443, 18539, 18959, 19793, 23431, 23629, 23993, 24419, 25127, 26737, 27407, 27739, 27799, 28409
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
a(3) = 241 is a term because it is prime, the next two primes are 251 and 257, and 2*241+251 = 733 and 2*241+257 = 739 are prime.
|
|
MAPLE
|
R:= NULL: count:= 0:
q:= 2: r:= 3:
while count < 100 do
p:= q; q:= r; r:= nextprime(r);
if isprime(2*p+q) and isprime(2*p+r) then
count:= count+1; R:= R, p;
fi
od:
R;
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|