OFFSET
2,1
FORMULA
Let F(n) := a(n)/A007504(n). Conjecture: as n tends to infinity F(n) tends to Pi/2 with Pi=3.14159......
MATHEMATICA
PrevPrime[ n_Integer] := Block[ {k = n - 1}, While[ ! PrimeQ[ k ], k-- ]; k ]; LF[ n_Integer ] := Block[ { p = Product[ Prime[ i ], {i, 1, n} ] - 1, q}, q = PrevPrime[ p ]; p - q + 1 ]; t = Table[LF[ n ], {n, 2, 48}]; Table[Plus @@ Take[t, n], {n, 47}] (* Robert G. Wilson v, Sep 04 2004 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Aug 29 2004
EXTENSIONS
More terms from Robert G. Wilson v, Sep 04 2004
STATUS
approved