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%I #19 Mar 05 2021 03:30:55
%S 91,93,94,95,97,901,902,903,905,906,907,910,911,913,914,915,917,919,
%T 921,922,923,926,929,930,933,934,935,937,938,939,941,942,943,946,947,
%U 949,951,953,955,957,958,959,962,965,966,967,969,970,971,973,974,977,978
%N Squarefree numbers beginning with 9.
%C Intersection of A005117 and A217402. - _Michel Marcus_, Sep 14 2013
%C Lower density is 1/(15*Pi^2), upper density is 2/(3*Pi^2). - _Charles R Greathouse IV_, Nov 05 2017
%H Amiram Eldar, <a href="/A077685/b077685.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[1000],SquareFreeQ[#]&&First[IntegerDigits[#]]==9&] (* _Harvey P. Dale_, Dec 15 2013 *)
%o (PARI) isok(n) = issquarefree(n) && (digits(n)[1] == 9); \\ _Michel Marcus_, Sep 14 2013
%Y Cf. A077677, A077678, A077679, A077680, A077681, A077682, A077683, A077684.
%K base,easy,nonn
%O 1,1
%A _Amarnath Murthy_, Nov 16 2002
%E More terms from _Sascha Kurz_, Jan 28 2003