A238332 Primes whose digits, after the first, form a nonprime number not occurring earlier.

11, 19, 127, 139, 149, 151, 157, 163, 181, 191, 193, 199, 233, 269, 277, 421, 487, 1117, 1123, 1129, 1153, 1171, 1187, 1201, 1213, 1217, 1231, 1237, 1249, 1259, 1279, 1289, 1291, 1297, 1301, 1303, 1319, 1321, 1327, 1361, 1381, 1399, 1423, 1427, 1429, 1447

Offset

1,1

Comments

The corresponding nonprime numbers are in A238333.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 (first 2700 terms from T. D. Noe)

Mathematica

t = {}; eList = {}; p = 7; While[Length[t] < 1000, p = NextPrime[p]; e = FromDigits[Rest[IntegerDigits[p]]]; If[! PrimeQ[e] && ! MemberQ[eList, e], AppendTo[t, p]; AppendTo[eList, e]]]; t

Prog

(Haskell)
a238332 n = a238332_list !! (n-1)
a238332_list = f [] $ drop 4 a000040_list where
   f xs (p:ps) | a010051 t == 1 || t `elem` xs = f xs ps
               | otherwise = p : f (t:xs) ps
               where t = read $ tail $ show p
-- Reinhard Zumkeller, Feb 28 2014

Crossrefs

Cf. A000040 (prime numbers), A238333.

Cf. A010051.

Sequence in context: A043968 A199329 A121132 * A089773 A048389 A163151

Adjacent sequences: A238329 A238330 A238331 * A238333 A238334 A238335

Keyword

nonn,base

Author

T. D. Noe, Feb 28 2014

Status

approved