The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A242772 The lesser of twin primes p1 such that 2*p1 + p2 is a prime number (A174913) and also the lesser of other twin primes in A174913. 2
 5, 11489, 32969, 33329, 33599, 42839, 58109, 93809, 96329, 114599, 180179, 272999, 309539, 334889, 401309, 540539, 633569, 717089, 784349, 820409, 870239, 879689, 907139, 948089, 989249, 991619, 994559, 1020959, 1028579, 1044749, 1185659, 1189649, 1245449, 1253909 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS It seems that a(n) == 9 mod 10 for n > 1. a(n) == 9 (mod 10) for n > 1 since if p1 == 1, 3 or 7 (mod 10) then 2*p1 + p2, p2, or 2*p1 + p2 + 2 is divisible by 5, respectively. - Amiram Eldar, Dec 31 2019 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 EXAMPLE a(1) = A174913(2) = 5 and 2*5 + 7 = 17 = A174913(3). MATHEMATICA Select[Range[10^6], And @@ PrimeQ[{#, # + 2, (p = 3*# + 2), p + 2, 3*p + 2}] &] (* Amiram Eldar, Dec 31 2019 *) PROG (PARI) isok(p) = isprime(p) && isprime(p+2) && isprime(q=3*p+2) && isprime(q+2) && isprime(3*q+2); \\ Michel Marcus, May 23 2014 CROSSREFS Cf. A001359, A174913, A174920, A242773. Sequence in context: A292742 A260262 A058051 * A089989 A219011 A297482 Adjacent sequences:  A242769 A242770 A242771 * A242773 A242774 A242775 KEYWORD nonn AUTHOR Ivan N. Ianakiev, May 22 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 23 01:31 EDT 2021. Contains 345394 sequences. (Running on oeis4.)