|
|
A065712
|
|
Number of 1's in decimal expansion of 2^n.
|
|
15
|
|
|
1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 2, 1, 0, 1, 1, 1, 0, 2, 0, 1, 2, 0, 1, 2, 1, 0, 0, 3, 0, 1, 1, 0, 1, 3, 1, 3, 0, 3, 1, 1, 1, 2, 2, 2, 2, 0, 1, 3, 1, 0, 4, 4, 0, 3, 1, 3, 0, 3, 3, 0, 2, 2, 3, 6, 3, 1, 0, 2, 3, 3, 5, 1, 1, 5, 3, 1, 2, 5, 1, 4, 2, 2, 5, 2, 0, 5, 3, 1, 6, 2, 2, 4, 5, 2
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,18
|
|
COMMENTS
|
2^17 = 131072 so a(17)=2.
|
|
LINKS
|
|
|
MATHEMATICA
|
Table[ Count[ IntegerDigits[2^n], 1], {n, 0, 100} ]
Table[DigitCount[2^n, 10, 1], {n, 0, 120}] (* Harvey P. Dale, Aug 15 2014 *)
|
|
PROG
|
(PARI) Count(x, d)= { local(c=0, f); while (x>9, f=x-10*(x\10); if (f==d, c++); x\=10); if (x==d, c++); return(c) }
{ for (n=0, 1000, a=Count(2^n, 1); write("b065712.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 26 2009
(PARI) a(n) = #select(x->(x==1), digits(2^n)); \\ Michel Marcus, Jun 15 2018
(Python)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|