|
|
A098160
|
|
Numbers n with property that when writing down all the natural numbers from 0 to n one uses the same number of even and odd digits.
|
|
0
|
|
|
1, 3, 5, 7, 9, 10, 28, 29, 30, 48, 49, 50, 68, 69, 70, 88, 89, 90
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
The sequence seems to stop at 90.
|
|
LINKS
|
|
|
EXAMPLE
|
[0,1,2,3,4,5,6,7,8,9,10] uses 6 even digits and 6 odd digits.
|
|
MATHEMATICA
|
f[n_] := Block[{id = Mod[ Flatten[ Table[ IntegerDigits[i], {i, 0, n}]], 2]}, Length[id] - 2Plus @@ id]; Select[ Range[ 100], f[ # ] == 0 &] (* Robert G. Wilson v, Nov 03 2004 *)
sneoQ[n_]:=Module[{d=Flatten[IntegerDigits/@Range[0, n]]}, 2*Count[ d, _?OddQ] == Length[d]]; Select[Range[100], sneoQ] (* Harvey P. Dale, Jul 31 2017 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,easy,nonn,fini,full
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|