A362100 Numbers k such that 8^k starts with k.

4, 10, 18, 652, 1299, 8225, 12949, 56230, 156277, 3227298, 144225157

Offset

1,1

Links

Table of n, a(n) for n=1..11.

Maple

filter:= proc(n) local d1, d2, t;
  t:= 8^n;
  d1:= ilog10(t);
  d2:= ilog10(n);
  floor(t/10^(d1-d2)) = n
end proc:
select(filter, [$1..10^5]); # Robert Israel, Apr 10 2023

Prog

(Python)
from itertools import count, islice
def A362100_gen(startvalue=1): # generator of terms >= startvalue
    a = 1<<3*(m:=max(startvalue, 1))
    for n in count(m):
        if (s:=str(n))==str(a)[:len(s)]:
            yield n
        a <<= 3
A362100_list = list(islice(A362100_gen(), 5)) # Chai Wah Wu, Apr 10 2023

Crossrefs

For k such that b^k starts with n, for b = 2,..., 9, see A100129, A362096, A320930, A362097-A362101.

Sequence in context: A318070 A073262 A353189 * A145731 A162958 A307395

Adjacent sequences: A362097 A362098 A362099 * A362101 A362102 A362103

Keyword

nonn,base,more

Author

N. J. A. Sloane, Apr 10 2023, based on an email from Keith F. Lynch.

Status

approved