A182689 a(n) = the smallest 2-digit number with exactly n divisors, a(n) = 0 if no such number exists.

0, 11, 25, 10, 16, 12, 64, 24, 36, 48, 0, 60, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,2

Links

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

Formula

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

12 = max n such that a(n) > 0, a(n) = 0 for n > 12.

Mathematica

With[{tbl=Table[{n, DivisorSigma[0, n]}, {n, 10, 99}]}, Table[SelectFirst[tbl, #[[2]]==k&], {k, 50}]][[;; , 1]]/."NotFound"->0 (* Harvey P. Dale, Jun 10 2026 *)

Crossrefs

Cf. A182690.

Sequence in context: A334597 A114167 A108302 * A251412 A286279 A125868

Adjacent sequences: A182686 A182687 A182688 * A182690 A182691 A182692

Keyword

nonn,base,less,changed

Author

Jaroslav Krizek, Nov 27 2010

Status

approved