(Python)
from math import factorial as fct
def trailing_zero(n):
k=0
while n!=0:
n//=5
k+=n
return k
index = 1
f = 1
while True:
if trailing_zero(f) == index:
print("
A255400("+str(index)+") = " +str(f))
index += 1
elif trailing_zero(f) > index:
while True:
clnzer = str(fct(f))[:-trailing_zero(f)]
if index*'0' in clnzer and (index+1)*'0' not in clnzer:
print("
A255400("+str(index)+") = " +str(f))
index += 1
f = 0
break
f +=1
f +=1
return
(Python)
import re
f, i, s = 1, 0, re.compile('[0-9]*[1-9]0{'+str(n)+'}[1-9][0-9]*')
while s.match(str(f)+'1') is None:
i += 1
f *= i
f(k, special, sz, sz1) = my(f=k!); if (special, s=Str(f/10^valuation(f, 10)), s=Str(k!)); #strsplit(s, sz) - #strsplit(s, sz1);
a(n) = if (n==0, return(0)); my(sz= concat(vector(n, k, "0")), sz1=concat(sz, "0"), k=1, special=is(n)); while (f(k, special, sz, sz1) != 1, k++); k; \\
Michel Marcus, Oct 25 2023
