A238331 The prime(n)-th prime number ending in prime(n), or 0 if none exists.

0, 23, 0, 107, 2411, 3413, 5417, 4919, 5923, 8629, 9931, 10937, 14741, 14243, 16747, 18553, 19259, 22961, 24767, 28571, 24373, 31079, 29483, 33589, 35597, 498101, 475103, 528107, 555109, 570113, 607127, 641131, 659137, 717139, 756149, 786151, 754157, 817163

Offset

1,2

Comments

The first number ending in prime(n) is, of course, prime(n). The numbers 2 and 5 are zero because there are no additional primes ending in those numbers; they are the numbers divisible by 2 or 5.

Links

T. D. Noe, Table of n, a(n) for n = 1..200

Example

23 is the third prime ending with 3.
107 is the seventh prime ending in 7.
2411 is the 11th prime ending in 11.
3413 is the 13th prime ending in 13 -- a very unlucky prime.

Mathematica

ps = Prime[Range[PrimePi[1000000]]]; t = {}; p = 1; done = False; While[! done, p = NextPrime[p]; len = Length[IntegerDigits[p]]; s = Select[ps, Mod[#, 10^len] == p &, p]; If[Length[s] < p, If[MemberQ[{2, 5}, p], AppendTo[t, 0], done = True], AppendTo[t, s[[-1]]]]]; t

Crossrefs

Cf. A000040 (prime numbers).

Cf. A030431, A030432, A167442 (primes ending in 3, 7, 11).

Sequence in context: A119566 A143196 A092993 * A114784 A141517 A040534

Adjacent sequences: A238328 A238329 A238330 * A238332 A238333 A238334

Keyword

nonn,base

Author

T. D. Noe, Feb 27 2014

Status

approved