%I #7 Mar 30 2012 18:39:03
%S 1,1,2,10,10,10,10,18,18,18,18,18,18,18,18,126,126,126,126,126,126,
%T 126,126,270,270,270,270,270,270,270,270,270,270,270,270,270,270,270,
%U 270,270,270,270,270,1470,1470,1470,1890,1890,1890,2310,2310,2310,2310
%N Smallest s such that sk+1 is squarefree for 1 <= k <= n.
%C a(n)+1 or a(n)-1 is prime for listed terms.
%o (PARI) for(n=1,57,s=1; while(sum(i=1,n,issquarefree(s*i+1))<n,s++); print1(s,","))
%K easy,nonn
%O 1,3
%A _Benoit Cloitre_, Jun 06 2002