OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..1064
EXAMPLE
6 is in the sequence as A171744(6) = 22 and 6*22 = 132. This is a record; no n less than 6 produces a product of at least 132.
MAPLE
f:= proc(p) local t, k;
t:= 1;
for k from 1 do
t:= t*p;
if nops(convert(convert(t, base, 10), set))=10 then return k fi;
od
end proc:
R:= NULL: m:= 0: p:= 1: count:= 0:
for k from 1 while count < 100 do
p:= nextprime(p);
v:= k*f(p);
if v > m then
R:= R, k;
m:= v;
count:= count+1
fi
od:
R; # Robert Israel, Aug 05 2024
MATHEMATICA
With[{s = Array[Block[{p = Prime@ #, k = 1}, While[Min@ DigitCount[p^k] == 0, k++]; k #] &, 1600]}, Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Aug 21 2020 *)
PROG
(PARI) f(n) = {my(k=1, p=prime(n)); while(#Set(digits(p^k))<10, k++); k; } \\ A171744
lista(nn) = {my(m=0, x); for (n=1, nn, x = n*f(n); if (x >m, m = x; print1(n, ", ")); ); } \\ Michel Marcus, Jan 26 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
David A. Corneth, Aug 14 2020
STATUS
approved