OFFSET
1,7
EXAMPLE
a(7) = 2: there are 2 primes viz. 2,3 which leave a remainder 1 on dividing 7.
MATHEMATICA
Table[Count[PrimeQ[DeleteCases[Table[Mod[w, Prime[j]], {j, 1, PrimePi[w]}], 0]], False], {w, 1, 256}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 01 2002
EXTENSIONS
More terms from Labos Elemer, Aug 02 2002
STATUS
approved