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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A004134 Denominators in expansion of (1-x)^{-1/4} are 2^a(n). 7
0, 2, 5, 7, 11, 13, 16, 18, 23, 25, 28, 30, 34, 36, 39, 41, 47, 49, 52, 54, 58, 60, 63, 65, 70, 72, 75, 77, 81, 83, 86, 88, 95, 97, 100, 102, 106, 108, 111, 113, 118, 120, 123, 125, 129, 131, 134, 136, 142, 144, 147, 149, 153, 155, 158, 160, 165, 167, 170, 172, 176, 178 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

LINKS

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

R. Stephan, Table of generating functions

FORMULA

3n - A000120(n). Recurrence: a(2n) = a(n) + 3n, a(2n+1) = a(n) + 3n + 2. Proved by Mitch Harris, following a conjecture by Ralf Stephan.

PROG

(PARI) {a(n) = if( n<0, 0, 3*n - subst( Pol( binary( n ) ), x, 1) ) } /* Michael Somos Aug 23 2007 */

CROSSREFS

Cf. A004130.

Sequence in context: A057922 A113543 A189468 * A191406 A157829 A020581

Adjacent sequences:  A004131 A004132 A004133 * A004135 A004136 A004137

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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

Content is available under The OEIS End-User License Agreement .

Last modified February 17 11:18 EST 2012. Contains 206011 sequences.