A182695 a(n) = the smallest 4-digit number with exactly n divisors, a(n) = 0 if no such number exists.

0, 1009, 1369, 1003, 2401, 1004, 0, 1001, 1089, 1053, 1024, 1012, 4096, 1088, 1936, 1000, 0, 1044, 0, 1040, 1600, 3072, 0, 1020, 1296, 0, 1764, 1344, 0, 1008, 0, 1080, 9216, 0, 5184, 1260, 0, 0, 0, 1680, 0, 2880, 0, 0, 3600, 0, 0, 2520, 0, 6480

Offset

1,2

Links

Table of n, a(n) for n=1..50.

Formula

A000005(a(n)) = n for a(n) > 0.

64 = max n such that a(n) > 0, a(n) = 0 for n > 64.

a(n) <= A182696(n).

Mathematica

digits=4; tbl=DivisorSigma[0, Range[10^(digits-1), 10^digits-1]]; t=Table[0, {Max[tbl]}]; offset=10^digits; Do[t[[tbl[[-i]]]]=offset-i, {i, Length[tbl]}]; t

Crossrefs

Cf. A182696.

Sequence in context: A325090 A024974 A025400 * A100776 A126238 A176930

Adjacent sequences: A182692 A182693 A182694 * A182696 A182697 A182698

Keyword

nonn,base

Author

Jaroslav Krizek, Nov 27 2010

Status

approved