OFFSET
1,1
COMMENTS
at n = 1,4,7,... and n = 2,5,8,... a(n) = 3; also n = 3,15,27,... and n = 6,18,30,... a(n) = 4; all other terms are apparently primes. In case k=1, for all n, a(n) = least prime divisor of n+1.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
re=Reap[Do[Do[If[Mod[n, k]>Mod[n+2, k], Sow[k]; Break[]], {k, 2, n+2}], {n, 300}]][[2, 1]]
lm[n_]:=Module[{m=2}, While[Mod[n, m]<=Mod[n+2, m], m++]; m]; Array[lm, 110] (* Harvey P. Dale, May 21 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 03 2006
STATUS
approved