OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1878 from Pierre CAMI)
EXAMPLE
563 is in the sequence since it is a prime number, and 563 - 2 = 561 is a Carmichael number.
1103 is in the sequence since it is a prime number, and 1103 + 2 = 1105 is a Carmichael number.
MATHEMATICA
s = {}; carmichaelQ[n_] := CompositeQ[n] && Divisible[n - 1, CarmichaelLambda[n]]; Do[If[carmichaelQ[n], If[PrimeQ[n - 2], AppendTo[s, n - 2]]; If[PrimeQ[n + 2], AppendTo[s, n + 2]]], {n, 10^6}]; s (* Amiram Eldar, Jul 07 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Dec 14 2007, corrected Jun 22 2008; Sep 17 2008
STATUS
approved