(SageMath)
def is_cyclops(n, base=10):
dg = n.digits(base) if n > 0 else [0]
return len(dg) % 2 == 1 and dg[len(dg)//2] == 0 and dg.count(0) == 1
is_
A134808 = lambda n: is_cyclops(n)
(PARI) a(n, {base=10}) = my (l=0); my (r=n-1); while (r >= (base-1)^(2*l), r -= (base-1)^(2*l); l++); return (base^(l+1) * ( (base^l-1)/(base-1) + if (base>2, fromdigits(digits(r \ ((base-1)^l), (base-1)), base)) ) + ( (base^l-1)/(base-1) + if (base>2, fromdigits(digits(r % ((base-1)^l), (base-1)), base)))) \\
Rémy Sigrist, Apr 29 2017
(Python)
from itertools import product
def cyclops(upto=float('inf'), upton=float('inf')): # generator
yield 0
c, n, half_digits, pow10 = 0, 1, 0, 10
while 100**(half_digits+1) < upto and n < upton:
half_digits += 1
pow10 *= 10
for left in product("123456789", repeat=half_digits):
left_plus_eye = int("".join(left))*pow10
for right in product("123456789", repeat=half_digits):
c, n = left_plus_eye + int("".join(right)), n+1
if c <= upto and n <= upton: yield c
print([c for c in cyclops(upto=606)])
