The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A087069 a(n) = Sum_{k >= 0} floor(n/(4^k)). 2
 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 21, 22, 23, 24, 26, 27, 28, 29, 31, 32, 33, 34, 36, 37, 38, 39, 42, 43, 44, 45, 47, 48, 49, 50, 52, 53, 54, 55, 57, 58, 59, 60, 63, 64, 65, 66, 68, 69, 70, 71, 73, 74, 75, 76, 78, 79, 80, 81, 85, 86, 87, 88, 90, 91, 92, 93 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 FORMULA a(n) = Sum_{k>=0} A030308(n,k)*A000975(k+1). - Philippe Deléham, Oct 16 2011 a(n) = A054893(4*n). - Vaclav Kotesovec, May 28 2014 G.f.: (1/(1 - x))*Sum_{k>=0} x^(4^k)/(1 - x^(4^k)). - Ilya Gutkovskiy, Mar 15 2018 EXAMPLE a(4) = 4 + floor(4/4) + floor(4/16) + floor(4/64) + ... = 5. MATHEMATICA Table[Sum[Floor[n/4^k], {k, 0, 1000}], {n, 0, 50}] (* G. C. Greubel, Oct 11 2017 *) PROG (Haskell) import Data.List (unfoldr) a087069 = sum . unfoldr (\x -> if x == 0 then Nothing else Just (x, x `div` 4)) -- Reinhard Zumkeller, Apr 22 2011 (PARI) for(n=0, 50, print1(sum(k=0, 1000, floor(n/4^k)), ", ")) \\ G. C. Greubel, Oct 11 2017 CROSSREFS Cf. A005187, A054893, A242954. Essentially partial sums of A115362. Sequence in context: A242491 A038129 A062071 * A023737 A037459 A020654 Adjacent sequences: A087066 A087067 A087068 * A087070 A087071 A087072 KEYWORD nonn AUTHOR Clark Kimberling, Aug 07 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 14 20:39 EDT 2024. Contains 371667 sequences. (Running on oeis4.)