OFFSET
2,1
FORMULA
a(n) = Sum_( log(p_i), i=primepi(n!)+1..primepi((n+1)!) ) / log(n!).
EXAMPLE
a(3) = floor(log(7436429)/log(6)) = floor(8.830..) = 8.
MATHEMATICA
Table[Floor[1/Log[n!] Plus @@ Table[Log[Prime[i]*1.], {i, PrimePi[n!] + 1, PrimePi[(n + 1)!]}]], {n, 2, 10}]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Olivier Gérard, Oct 29 2017
STATUS
approved