OFFSET
1,1
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
FORMULA
Asymptotics: For any n, let f(n) be the number of entries in this sequence that are less than n. Then f(n)/n approaches 1 as n goes to infinity. This is because among numbers with a large number of digits, almost all have 0's in both odd positions and even positions. - David Wasserman, Jan 16 2002
EXAMPLE
2364 is a member as 2*6 = 3*4.
PROG
(Python)
from math import prod
def ok(n):
s = str(n)
return s != '1' and prod(map(int, s[::2])) == prod(map(int, s[1::2]))
print([k for k in range(1010) if ok(k)]) # Michael S. Branicky, Nov 22 2021
CROSSREFS
KEYWORD
base,nonn,easy
AUTHOR
Amarnath Murthy, Dec 29 2001
EXTENSIONS
Corrected by David Wasserman, Jan 16 2002
More terms from Sascha Kurz, Mar 23 2002
STATUS
approved