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 A077647 Smallest term of a run of at least 8 consecutive integers which are not squarefree. 11
 1092747, 7216618, 8870024, 8870025, 14379271, 22635347, 24816974, 25047846, 33678771, 33908368, 33908369, 34394371, 34682346, 37923938, 49250144, 49250145, 53379270, 69147868, 69147869, 70918820, 70918821, 71927247, 72913022, 83605071, 85972019, 90571646 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA A077647 = { A077640[k] | A077640[k+1] = A077640[k]+1 }. - M. F. Hasler, Feb 01 2016 EXAMPLE n=8870024: squares dividing n+j (j=0...8) i.e. 9 consecutive integers are as follows {4,25,121,841,4,49,961,9,16} MATHEMATICA s8[x_] := Apply[Plus, Table[Abs[MoebiusMu[x+j]], {j, 0, 7}]] If[Equal[s, 0], Print[n]], {n, 1000000, 100000000}] Flatten[Position[Partition[SquareFreeQ/@Range[91000000], 8, 1], _?(Union[#]=={False}&), {1}, Heads->False]] PROG (PARI) for(n=1, 10^8, forstep(k=7, 0, -1, issquarefree(n+k)&&(n+=k)&&next(2)); print1(n", ")) \\ M. F. Hasler, Feb 03 2016 CROSSREFS Cf. A013929, A051681. Cf. A045882 (first k-chain), A068781 (2-chains), A070258 (3-chains), A070284 (4-chains), A078144 (5-chains), A049535 (6-chains), A077640 (7-chains), A077647 (8-chains), A078143 (9-chains), A268313 (10-chains), A268314 (11-chains). Sequence in context: A224592 A252119 A109148 * A172647 A172754 A268036 Adjacent sequences:  A077644 A077645 A077646 * A077648 A077649 A077650 KEYWORD nonn AUTHOR Labos Elemer, Nov 18 2002 STATUS approved

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