A162529 Numbers k whose largest divisor <= sqrt(k) equals 9.

81, 90, 99, 108, 117, 126, 135, 153, 162, 171, 189, 207, 243, 261, 279, 333, 369, 387, 423, 477, 531, 549, 603, 639, 657, 711, 747, 801, 873, 909, 927, 963, 981, 1017, 1143, 1179, 1233, 1251, 1341, 1359, 1413, 1467, 1503, 1557, 1611, 1629, 1719, 1737, 1773

Offset

1,1

Comments

See A161344 for more information.

Links

Table of n, a(n) for n=1..49.

Formula

Numbers k such that A033676(k)=9.

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) = 9 then printf("%d, ", n) ; fi; od: # R. J. Mathar, Jul 13 2009

Mathematica

lst = {}; For[n = 1, n <= 5000, n++, If[Last[Select[Divisors[n], # <= Sqrt@n &]] == 9, PrependTo[lst, n]]]; Reverse@lst (* Jasper Mulder (jasper.mulder(AT)planet.nl), Jul 14 2009 *)

Crossrefs

Cf. A033676, A008578, A161344, A161345, A161424, A161835, A162526, A162527, A162528, A162530, A162531, A162532.

Sequence in context: A124968 A294577 A044865 * A243260 A335066 A179444

Adjacent sequences: A162526 A162527 A162528 * A162530 A162531 A162532

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