OFFSET
0,1
EXAMPLE
0.91529479751356057973361539728562081112510204536957775...
MATHEMATICA
N[Sum[If[And[PrimeQ[6*k - 1], PrimeQ[6*k + 1]], 1, 0]*2^(-k), {k, 1, 500}], 110]
CROSSREFS
KEYWORD
AUTHOR
Joseph Biberstine (jrbibers(AT)indiana.edu), Nov 22 2004
STATUS
approved