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A111070
Twin prime pairs using digits 1 and 3 only.
1
11, 13, 311, 313, 131111, 131113, 313331, 313333, 1131131, 1131133, 3331331, 3331333, 3333131, 3333133, 3333311, 3333313, 111113111, 111113113, 113331311, 113331313, 331313111, 331313113, 331331111, 331331113, 333331331, 333331333
OFFSET
1,1
COMMENTS
Both the members of the twin prime pairs are included.
LINKS
FORMULA
a(2k) = a(2k-1) + 2.
MATHEMATICA
s = Select[Flatten @ Table[FromDigits /@ Tuples[{1, 3}, k], {k, 1, 9}], And @@ PrimeQ[10 # + {1, 3}] &]; Flatten @ Transpose @ {10 s + 1, 10 s + 3} (* Amiram Eldar, Dec 28 2019 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jan 02 2006
EXTENSIONS
Corrected and extended by Farideh Firoozbakht, Jan 05 2006
STATUS
approved