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%I #38 Jan 03 2021 01:33:02
%S 3475,18271,25524,25623,45616,55772,72471,72472,104419,121667,133223,
%T 133224,149220,164975,165568,165571,172916,180167,180168,203979,
%U 203980,219123,260424,261472,261475,334516,334519,364216,381267,393320,393323,402723,412524,420467,420468
%N Numbers k such that at least 7 of k, k+1, ..., k+9 are divisible by their least prime factor squared.
%H David A. Corneth, <a href="/A328817/b328817.txt">Table of n, a(n) for n = 1..10000</a> (first 600 terms from Harvey P. Dale)
%e 203980 is a member since 2^2 | 203980, 37^2 | 203981, 13^2 | 203983, 2^2 | 203984, 3^2 | 203985, 7^2 | 203987, and 2^2 | 203988.
%t Flatten[Position[Partition[Table[If[Divisible[n,FactorInteger[n][[1,1]]^2],1,0],{n,420000}],10,1],_?(Total[#]>6&)]] (* _Harvey P. Dale_, Jan 02 2021 *)
%o (PARI) upto(n) = {my(l, c, res); l = List([0,0,0,1,0,0,0,1,1,0]); c = 3; res = List(); for(i = 11, n, f = factor(i)[,2]; c -= l[1]; listpop(l, 1); if(f[1] >= 2, c++; listput(l, 1) , listput(l, 0) ); if(c >= 7, listput(res, i-9); ) ); res } \\ _David A. Corneth_, Jan 02 2021
%Y Cf. A283050.
%K nonn
%O 1,1
%A _Sean A. Irvine_ (on behalf of _Donald S. McDonald_), Nov 07 2019
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