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A181606
Twin primes ending in 9.
5
19, 29, 59, 109, 139, 149, 179, 199, 229, 239, 269, 349, 419, 569, 599, 619, 659, 809, 829, 859, 1019, 1049, 1229, 1279, 1289, 1319, 1429, 1489, 1609, 1619, 1669, 1699, 1789, 1879, 1949, 1999, 2029, 2089, 2129, 2239, 2269, 2309, 2339, 2549, 2659, 2689
OFFSET
1,1
MAPLE
filter:= proc(n)
if not isprime(n) then return false fi;
if n mod 3 = 1 then isprime(n-2) else isprime(n+2) fi
end proc:
select(filter, [seq(i, i=9..10^4, 10)]); # Robert Israel, Nov 19 2023
MATHEMATICA
Select[Prime@ Range@ 800, Mod[ #, 10] == 9 && (PrimeQ[ # - 2] || PrimeQ[ # + 2]) &] (* Robert G. Wilson v, Nov 06 2010 *)
Select[Union[Flatten[Select[Partition[Prime[Range[400]], 2, 1], #[[2]]-#[[1]]==2&]]], Mod[#, 10]==9&] (* Harvey P. Dale, May 21 2024 *)
CROSSREFS
Union of A060229 and A282324.
Sequence in context: A287313 A136071 A088998 * A139886 A089724 A265804
KEYWORD
nonn
AUTHOR
Omar E. Pol, Nov 01 2010
EXTENSIONS
More terms from Robert G. Wilson v, Nov 06 2010
STATUS
approved