OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..3000
EXAMPLE
a(5)=500 since 500 has prime factorization 500=2*2*5*5*5 (5 factors) and begins with 5 and is the smallest such number.
MAPLE
f:= proc(n) uses priqueue;
local pq, d, t, v, dv, i, p;
d:= ilog10(n);
initialize(pq);
insert([-2^n, 2, n], pq);
do
t:= extract(pq);
v:= -t[1];
dv:= ilog10(v);
if floor(v/10^(dv-d))=n then return v fi;
p:= nextprime(t[2]);
for i from 1 to t[3] do
insert([t[1]*(p/t[2])^i, p, i], pq);
od;
od;
end proc:
map(f, [$1..40]); # Robert Israel, Jul 23 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Erich Friedman, Aug 07 2005
EXTENSIONS
a(24)-a(33) from Donovan Johnson, Apr 27 2008
STATUS
approved