OFFSET
2,7
COMMENTS
a(n)=0 iff n is prime.
LINKS
R. Zumkeller, Table of n, a(n) for n = 2..10000
MATHEMATICA
a[n_] := (n - NextPrime[n+1, -1])*(NextPrime[n] - n); Table[a[n], {n, 2, 103}] (* Jean-François Alcover, Jun 14 2013 *)
CROSSREFS
KEYWORD
AUTHOR
Reinhard Zumkeller, Jul 01 2002
STATUS
approved