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A023415
If any power of 2 ends with k 8's and 9's, they must be the first k terms of this sequence in reverse order.
5
8, 8, 8, 9, 8, 9, 9, 8, 9, 8, 9, 8, 8, 9, 9, 8, 9, 8, 9, 9, 9, 8, 8, 8, 8, 9, 8, 8, 8, 8, 9, 9, 9, 9, 8, 9, 8, 8, 9, 9, 8, 8, 9, 9, 8, 9, 8, 8, 9, 8, 9, 8, 9, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 8, 9, 8, 8, 8, 9, 9, 8, 8, 9, 8, 8, 9, 9, 8, 8, 9, 9, 9, 8, 9, 9, 9, 9, 9, 9, 8, 8, 9, 8, 8, 9, 9, 9, 9, 9, 9, 8, 8, 8, 9, 9, 8, 8, 8
OFFSET
1,1
COMMENTS
Upper limit of backward value of 2^n and n!. - Simon Plouffe, Mar 23 2009
LINKS
PROG
(Python)
# upper limit of backward value of 2^n
a, i=8, 0; x=a
while i < 200:
i+=1; print(x, end=', ')
if a%2**(i+1) == 0: x=8
else: x=9
a+=x*10**i
# Cezary Glowacz, Mar 11 2017
CROSSREFS
Cf. A145679.
Sequence in context: A248762 A186985 A203127 * A294659 A134314 A242891
KEYWORD
nonn,base
STATUS
approved