|
|
A063577
|
|
Smallest k such that 4^k has exactly n 2's in its decimal representation.
|
|
1
|
|
|
1, 4, 9, 25, 36, 54, 45, 56, 68, 106, 87, 98, 100, 203, 140, 154, 160, 174, 165, 263, 246, 243, 157, 234, 276, 280, 338, 308, 343, 371, 335, 299, 427, 394, 497, 475, 473, 405, 524, 467, 577, 485, 586, 509, 492, 644, 464, 677, 563, 616, 582
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
MATHEMATICA
|
a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 2] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
With[{nk2=Table[{k, DigitCount[4^k, 10, 2]}, {k, 700}]}, Table[SelectFirst[nk2, #[[2]] == n&], {n, 0, 50}]][[All, 1]] (* Harvey P. Dale, Jan 21 2023 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|