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