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Numbers k whose largest divisor <= sqrt(k) is 11.
18

%I #9 Apr 14 2020 03:32:12

%S 121,132,143,154,165,176,187,198,209,220,231,242,253,275,297,319,341,

%T 363,385,407,451,473,517,539,583,605,649,671,737,781,803,847,869,913,

%U 979,1067,1111,1133,1177,1199,1243,1331,1397,1441,1507,1529,1639,1661

%N Numbers k whose largest divisor <= sqrt(k) is 11.

%C See A161344 for more information.

%F Numbers k such that A033676(k)=11.

%p A033676 := proc(n) local dvs; dvs := sort(convert(numtheory[divisors](n),list)) ; op(floor((nops(dvs)+1)/2) ,dvs) ; end: for n from 1 to 2500 do if A033676(n) = 11 then printf("%d,",n) ; fi; od: # _R. J. Mathar_, Jul 13 2009

%t ld = 11;

%t selQ[n_] := AllTrue[Divisors[n], # <= ld || #^2 > n&];

%t Select[ Range[ld, 200] ld, selQ] (* _Jean-François Alcover_, Apr 14 2020 *)

%Y Cf. A033676, A008578, A161344, A161345, A161424, A161835, A162526, A162527, A162528, A162529, A162530, A162532.

%K easy,nonn

%O 1,1

%A _Omar E. Pol_, Jul 05 2009

%E More terms from _R. J. Mathar_ and Jasper Mulder (jasper.mulder(AT)planet.nl), Jul 13 2009