OFFSET
0,2
COMMENTS
a(n) = A006995(10^n).
LINKS
Chai Wah Wu, Table of n, a(n) for n = 0..500
PROG
(Python)
def A373448(n):
if n == 0: return 0
k = 10**n
a = 1<<(l:=k.bit_length()-2)
m = a|(k&a-1)
return (m<<l+1)+int(bin(m)[:1:-1]or'0', 2) if a&k else (m<<l)+int(bin(m)[-2:1:-1]or'0', 2)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Chai Wah Wu, Jun 14 2024
STATUS
approved