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%I #14 Dec 31 2018 03:50:45
%S 15,33,91,213,213,893,893,1343
%N Start of first occurrence of n consecutive odd squarefree composite numbers.
%C The sequence is finite because among 9 or more consecutive odd numbers there is always a multiple of 3*3. - _Rémy Sigrist_, Dec 19 2018
%e a(1) = 15 = A024556(1).
%e a(2) = 33 because 33 = 3*11 and 35 = 5*7 is the smallest pair of odd squarefree composite numbers. 31 and 37 are prime.
%e a(8) = 1343: 1343=17*79, 1345=5*269, 1347=3*449, 1349=19*71, 1351=7*193, 1353=3*11*41, 1355=5*271, 1357=23*59, whereas 1341=3^2*149 and 1359=3^2*151 are not squarefree.
%t a[n_] := For[k = 1, True, k = k+2, If[AllTrue[Range[k, k+2(n-1), 2], CompositeQ[#] && SquareFreeQ[#]&], Return[k]]];
%t Array[a, 8] (* _Jean-François Alcover_, Dec 31 2018 *)
%Y Cf. A024556, A321617.
%K nonn,fini,full
%O 1,1
%A _Hugo Pfoertner_, Dec 19 2018
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