|
|
A182671
|
|
a(n) = the smallest n-digit number with exactly 6 divisors, a(n) = 0 if no such number exists.
|
|
1
|
|
|
0, 12, 116, 1004, 10012, 100017, 1000028, 10000036, 100000036, 1000000017, 10000000004, 100000000017, 1000000000028, 10000000000036, 100000000000019, 1000000000000025, 10000000000000091, 100000000000000028, 1000000000000000179, 10000000000000000196
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
a(n) = the smallest n-digit number of the form p^5 or p^2*q^1, (p, q = distinct primes), a(n) = 0 if no such number exists.
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Table[k=10^(n-1); While[k<10^n && DivisorSigma[0, k] != 6, k++]; If[k==10^n, k=0]; k, {n, 10}]
|
|
CROSSREFS
|
Cf. A182672 (largest n-digit number with exactly 6 divisors).
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|