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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A120785 Denominators of partial sums of Catalan numbers scaled by powers of 1/16. 6
1, 16, 128, 4096, 32768, 524288, 4194304, 268435456, 2147483648, 34359738368, 274877906944, 8796093022208, 70368744177664, 1125899906842624, 9007199254740992, 1152921504606846976 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Numerators are given under A120784.

The listed numbers coincide with the denominators of sum(C(k)/(-16)^k,k=0..n). For the numerators see A120794. In general these denominators may be different. See e.g. A120783 versus A120793 and A120787 versus A120796.

Also one fourth of denominators of partial sums for sqrt(2)+sqrt(3). See A121503 for the numerators.

FORMULA

a(n)=denominator(r(n)), with the rationals r(n):=sum(C(k)/16^k,k=0..n) with C(k):=A000108(k) (Catalan numbers).

CROSSREFS

Sequence in context: A132136 A163399 A067488 * A031156 A099195 A041486

Adjacent sequences:  A120782 A120783 A120784 * A120786 A120787 A120788

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Jul 20 2006

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 16 21:51 EST 2012. Contains 205978 sequences.