OFFSET
1,2
COMMENTS
First 4 occurs at n=12720, first 5 occurs at n=19440. See A074200.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..21000
EXAMPLE
a(12) = 3 as 13 = 1*prime, 14 = 2*prime, 15 = 3*prime.
MATHEMATICA
Table[If[CompositeQ[n + 1], 0, k = 1; While[Times @@ Boole@ Map[PrimeQ, MapIndexed[#1/First@ #2 &, (n + Range@ k)]] == 1, k++]; k - 1], {n, 120}] (* Michael De Vlieger, Dec 01 2016 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 30 2016
STATUS
approved