A238204 Even numbers n such that the difference with the preceding prime is prime.

10, 16, 22, 26, 28, 34, 36, 40, 46, 50, 52, 56, 58, 64, 66, 70, 76, 78, 82, 86, 88, 92, 94, 96, 100, 106, 112, 116, 118, 120, 124, 126, 130, 134, 136, 142, 144, 146, 154, 156, 160, 162, 166, 170, 172, 176, 178, 184, 186, 188, 196, 202, 204, 206, 210, 214, 216

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

28 is in the list because 23 is the greatest prime less than 28 and 28 - 23 = 5 is also prime.

Maple

a:= proc(n) option remember; local k;
      for k from `if`(n=1, 4, a(n-1)+2) by 2
      while not isprime(k-prevprime(k)) do od; k
    end:
seq(a(n), n=1..60);  # Alois P. Heinz, Mar 03 2014

Mathematica

Select[Range[99] 2, PrimeQ[# - NextPrime[#, -1]] &] (* Giovanni Resta, Feb 22 2014 *)

Crossrefs

Sequence in context: A129848 A004261 A083118 * A242057 A245024 A264721

Adjacent sequences: A238201 A238202 A238203 * A238205 A238206 A238207

Keyword

nonn

Author

Franz Vrabec, Feb 20 2014

Status

approved