A250025 Lesser of twin prime pairs of the form (40n - 21, 40n - 19).

59, 179, 419, 659, 1019, 1619, 2339, 3299, 3539, 4019, 4259, 5099, 6299, 6659, 6779, 8219, 8819, 9419, 10139, 10499, 10859, 11699, 11939, 12539, 16139, 16979, 17579, 18059, 18539, 19139, 19379, 21059, 22619, 22739, 22859, 24179, 24419, 26699, 27059, 27539, 28619, 32939, 33179, 34259, 34499, 36779, 36899, 37019, 38459

Offset

1,1

Comments

This is a subsequence and the intersection of A001359 (lesser of twin primes) and A142190 (primes 19 mod 40).

Links

Karl V. Keller, Jr., Table of n, a(n) for n = 1..10000

Chris K. Caldwell, Twin primes

Eric Weisstein's World of Mathematics, Twin Primes

Mathematica

Select[40Range[1000] - 21, PrimeQ[#] && PrimeQ[# + 2] &] (* Alonso del Arte, Nov 11 2014 *)
Select[Table[40n-{19, 21}, {n, 1000}], AllTrue[#, PrimeQ]&][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 08 2019 *)

Prog

(Python)  from sympy import isprime
for n in range(1, 1001):
  if isprime(40*n-21) and isprime(40*n-19): print(40*n-21, end=", ")

Crossrefs

Cf. A142190, A001359.

Sequence in context: A341659 A279099 A142799 * A140626 A160681 A142857

Adjacent sequences: A250022 A250023 A250024 * A250026 A250027 A250028

Keyword

nonn

Author

Karl V. Keller, Jr., Nov 10 2014

Status

approved