OFFSET
1,1
COMMENTS
Odd numbers complementary to A185208.
Lim_{n->inf.} a(n)/n > 6/(1 + Sum_{j>=1} (2/(2^(2j+1)-1))) ~ 4.375745.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
2n < a(n) < 5n. For n > 51, 4.3n < a(n) < 4.5n. - Charles R Greathouse IV, Sep 05 2015
MATHEMATICA
lmt = 310; Take[ Union@ Flatten@ Table[ (2j - 1)(2^k - 1), {j, lmt/4}, {k, 2, 1 + Log2[ lmt/(2j)] }], 68] (* Michael De Vlieger, Sep 04 2015 *) (* and modified by Robert G. Wilson v, Sep 05 2015 *)
PROG
(PARI) list(lim)=my(v=List(), t); for(k=2, logint(lim\1+1, 2), t=2^k-1; forstep(j=1, lim\t, 2, listput(v, t*j))); Set(v) \\ Charles R Greathouse IV, Sep 05 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Bob Selcoe, Sep 04 2015
STATUS
approved