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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093302 a(n) = (a(n-1)+(2n-1))*(2n) with a(0)=0. 0
0, 2, 20, 150, 1256, 12650, 151932, 2127230, 34035920, 612646866, 12252937700, 269564629862, 6469551117240, 168208329048890, 4709833213369676, 141294996401091150, 4521439884834917792, 153728956084387206050 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

2 * [e^(1/2) * n! * 2^n] - 2n - 2.

E.g.f.: (2x+4x^2)/(1-2x) * exp(x).

PROG

(PARI) a(n)=2*floor(exp(1/2)*n!*2^n)-2*n-2

CROSSREFS

a(n) = A007566(n)-1 = 2*A010844(n)-2n-2. Bisection of A077138.

Sequence in context: A198647 A081159 A105489 * A093130 A043029 A164944

Adjacent sequences:  A093299 A093300 A093301 * A093303 A093304 A093305

KEYWORD

easy,nonn

AUTHOR

Emrehan Halici (emrehan(AT)halici.com.tr), Apr 24 2004

EXTENSIONS

Edited by Ralf Stephan, Apr 26 2004

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 09:50 EST 2012. Contains 205904 sequences.