OFFSET
1,1
COMMENTS
Numbers with exactly two runs of 1's in binary. - Franklin T. Adams-Watters, Dec 09 2013
MATHEMATICA
Select[Range[250], Length[Split[IntegerDigits[#, 2]]]==4&]/2 (* Harvey P. Dale, Aug 25 2016 *)
PROG
(PARI) runs(n)=my(s); while(n, n>>=valuation(if(n%2, n+1, n), 2); s++); s
is(n)=runs(n>>valuation(n, 2))==3 \\ Charles R Greathouse IV, Dec 09 2013
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved