The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A182694 a(n) = the largest 3-digit number with exactly n divisors, a(n) = 0 if no such number exists. 1
 0, 997, 961, 998, 625, 981, 729, 999, 676, 976, 0, 996, 0, 832, 784, 984, 0, 980, 0, 912, 576, 0, 0, 990, 0, 0, 900, 960, 0, 720, 0, 840, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS max {n : a(n) > 0} = 32, a(n) = 0 for n > 32. LINKS FORMULA a(n) = max {99 < k < 1000 : A000005(k)=n} if set is nonempty, else a(n) = 0. MAPLE with (numtheory): b:= n-> `if` (type (n, integer), n, 0): a:= n-> b (max (select (x-> tau(x)=n, [\$100..999])[])): seq (a(n), n=1..60); MATHEMATICA digits=3; tbl=DivisorSigma[0, Range[10^(digits-1), 10^digits-1]]; t=Table[0, {Max[tbl]}]; offset=10^(digits-1)-1; Do[t[[tbl[[i]]]]=i+offset, {i, Length[tbl]}]; t (With[{tb=Table[{n, DivisorSigma[0, n]}, {n, 999, 100, -1}]}, Table[SelectFirst[ tb, #[[2]]==k&], {k, 60}]]/.Missing["NotFound"]->{0, 0})[[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 02 2019 *) CROSSREFS Cf. A000005, A182693. Sequence in context: A028513 A267119 A210315 * A234847 A057698 A106763 Adjacent sequences:  A182691 A182692 A182693 * A182695 A182696 A182697 KEYWORD nonn,base AUTHOR Jaroslav Krizek, Nov 27 2010 EXTENSIONS Edited by Alois P. Heinz, Nov 27 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 22 22:24 EDT 2020. Contains 337291 sequences. (Running on oeis4.)