login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A049039 Geometric Connell sequence: 1 odd, 2 even, 4 odd, 8 even, ... 8
1, 2, 4, 5, 7, 9, 11, 12, 14, 16, 18, 20, 22, 24, 26, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 121, 123, 125 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Reinhard Zumkeller, Rows n=1..13 of triangle, flattened

R. Stephan, Some divide-and-conquer sequences ...

R. Stephan, Table of generating functions

FORMULA

a(n) = 2n-1-floor(log_2(n)). a(2^n-1) = 2^(n+1)-(n+2), the Eulerian numbers

a(0)=0, a(2n) = a(n) + 2n - 1, a(2n+1) = a(n) + 2n + 1. - Ralf Stephan, Oct 11 2003

MAPLE

Digits := 100: [seq(2*n-1-floor(evalf(log(n)/log(2))), n=1..100)];

MATHEMATICA

a[0] = 0; a[n_?EvenQ] := a[n] = a[n/2]+n-1; a[n_?OddQ] := a[n] = a[(n-1)/2]+n; Table[a[n], {n, 1, 100}] (* Jean-Fran├žois Alcover, Dec 27 2011, after Ralf Stephan *)

PROG

(Haskell)

a049039 n k = a049039_tabl !! (n-1) !! (k-1)

a049039_row n = a049039_tabl !! (n-1)

a049039_tabl = f 1 1 [1..] where

   f k p xs = ys : f (2 * k) (1 - p) (dropWhile (<= last ys) xs) where

     ys  = take k $ filter ((== p) . (`mod` 2)) xs

-- Reinhard Zumkeller, Jan 18 2012, Jul 08 2011

CROSSREFS

Cf. A001614, A033292, A030196, A000295, A050487, A050488.

Contribution from Johannes W. Meijer, May 24 2009: (Start)

Cf. A160464, A160465 and A160473.

(End)

Sequence in context: A083026 A047379 A093848 * A005152 A060831 A073727

Adjacent sequences:  A049036 A049037 A049038 * A049040 A049041 A049042

KEYWORD

easy,nonn,nice,tabf

AUTHOR

James A. Sellers

EXTENSIONS

Keyword tabf added by Reinhard Zumkeller, Jan 22 2012

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified September 26 15:27 EDT 2017. Contains 292531 sequences.