login
A162531
Numbers k whose largest divisor <= sqrt(k) is 11.
18
121, 132, 143, 154, 165, 176, 187, 198, 209, 220, 231, 242, 253, 275, 297, 319, 341, 363, 385, 407, 451, 473, 517, 539, 583, 605, 649, 671, 737, 781, 803, 847, 869, 913, 979, 1067, 1111, 1133, 1177, 1199, 1243, 1331, 1397, 1441, 1507, 1529, 1639, 1661
OFFSET
1,1
COMMENTS
See A161344 for more information.
FORMULA
Numbers k such that A033676(k)=11.
MAPLE
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
MATHEMATICA
ld = 11;
selQ[n_] := AllTrue[Divisors[n], # <= ld || #^2 > n&];
Select[ Range[ld, 200] ld, selQ] (* Jean-François Alcover, Apr 14 2020 *)
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Jul 05 2009
EXTENSIONS
More terms from R. J. Mathar and Jasper Mulder (jasper.mulder(AT)planet.nl), Jul 13 2009
STATUS
approved