OFFSET
1,1
COMMENTS
a(1) = 139 is the first prime separated from the next prime (149) by a composite number (9) of successive composites, namely, 140, 141, 142, 143, 144, 145, 146, 147, 148.
MATHEMATICA
ps = Prime[Range[500]]; pos = Position[Differences[ps] - 1, _?(# > 1 && ! PrimeQ[#] &)]; ps[[Flatten[pos]]] (* T. D. Noe, Mar 21 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Mar 21 2012
STATUS
approved