OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..63
PROG
(Python 3.8+)
from math import isqrt
def A343725(n):
m = isqrt(8*(10**i-1)//9)
m -= m % 2
k = m**2
s = set('02468')
while not set(str(k)) <= s:
m -= 2
k -= 4*(m+1)
return k # Chai Wah Wu, May 20 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jon E. Schoenfield, May 19 2021
STATUS
approved