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%I #17 Jul 09 2023 16:27:17
%S 26,362,926,1027,1126,1574,1774,1814,2059,2402,3482,3574,4166,4474,
%T 5042,5045,5374,5426,5914,6274,6326,6418,6626,6649,7226,7694,7985,
%U 8182,8674,9026,9458,9557,9874,9946,10774,10826,11851,12223,12494,12574,12949,13349,13474,13526,13582
%N Semiprimes k such that none of k-2, k-1, k+1, and k+2 is squarefree.
%e 24 = 2^3 * 3, 25 = 5^2, 26 = 2 * 13, 27 = 3^3, 28 = 2^2 * 7, so 26 is a term.
%e 360 = 2^3 * 3^2 * 5, 361 = 19^2, 362 = 2 * 181, 363 = 3 * 11^2, 364 = 2^2 * 7 * 13, so 362 is a term.
%t Select[Range[14000], PrimeOmega[#] == 2 && ! AnyTrue[# + {-2, -1, 1, 2}, SquareFreeQ] &] (* _Amiram Eldar_, Jul 01 2023 *)
%Y Cf. A001358, A013929, A153215. Subsequence of A364025.
%K nonn
%O 1,1
%A _Massimo Kofler_, Jul 01 2023
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