login
A367295
Numbers k such that 6 is the first digit of 2^k.
4
6, 16, 26, 36, 79, 89, 99, 109, 119, 129, 139, 182, 192, 202, 212, 222, 232, 275, 285, 295, 305, 315, 325, 335, 368, 378, 388, 398, 408, 418, 428, 471, 481, 491, 501, 511, 521, 564, 574, 584, 594, 604, 614, 624, 667, 677, 687, 697, 707, 717, 760, 770, 780, 790
OFFSET
1,1
COMMENTS
The asymptotic density of this sequence is log_10(7/6) = 0.066946...
MAPLE
x := 1:
L := []:
for n from 0 to 10^3 do
if 6 <= x and x < 7 then
L := [op(L), n]
fi;
x := 2*x;
if x > 10 then
x := (1/10)*x fi;
od:
L;
MATHEMATICA
Select[Range[800], IntegerDigits[2^#][[1]] == 6 &] (* Amiram Eldar, Nov 12 2023 *)
KEYWORD
nonn,base
AUTHOR
Martin Renner, Nov 12 2023
STATUS
approved