OFFSET
0,1
FORMULA
a(n) = A118479(n+1) - 10^n.
EXAMPLE
10^1 + 1 = 11; 11 is a Sophie Germain prime and 11 and 13 are twin prime pairs.
MATHEMATICA
f[n_] := Block[{k = 10^(n - 1)}, While[ !PrimeQ[k] || !PrimeQ[k + 2] || !PrimeQ[2k + 1], k++ ]; k - 10^(n - 1)]; Array[f, 40] (* Robert G. Wilson v, May 13 2006 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, May 07 2006
STATUS
approved