The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A098646 Trace sequence of 3 X 3 Krawtchouk matrix. 4
 3, 2, 12, 8, 48, 32, 192, 128, 768, 512, 3072, 2048, 12288, 8192, 49152, 32768, 196608, 131072, 786432, 524288, 3145728, 2097152, 12582912, 8388608, 50331648, 33554432, 201326592, 134217728, 805306368, 536870912, 3221225472, 2147483648 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Let A=[1,1,1;2,0,-2;1,-1,1], the 3 X 3 Krawtchouk matrix. Then a(n)=trace(A^n). LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (0,4) FORMULA G.f.: (3+2*x)/((1+2*x)*(1-2*x)). a(n) = (-2)^n+2*2^n. Recurrence: a(n) = 4a(n-2), a(0)=3, a(1)=2. - Ralf Stephan, Jul 17 2013 a(2n+1)=A081294(n+1). a(2n)=A002001(n+1). - R. J. Mathar, Nov 11 2013 PROG (MAGMA) [(-2)^n+2*2^n: n in [0..45]]; // Vincenzo Librandi, Jun 11 2011 CROSSREFS Cf. A074535, A098647. Sequence in context: A122407 A232752 A195200 * A129925 A258206 A267011 Adjacent sequences:  A098643 A098644 A098645 * A098647 A098648 A098649 KEYWORD easy,nonn AUTHOR Paul Barry, Sep 18 2004 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 8 14:52 EDT 2020. Contains 333314 sequences. (Running on oeis4.)