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A106664 G.f. (1-3*x+x^2)/((x-1)*(x+1)*(2*x^2-2*x+1)). 0
-1, 1, 2, 5, 4, 1, -8, -15, -16, 1, 32, 65, 64, 1, -128, -255, -256, 1, 512, 1025, 1024, 1, -2048, -4095, -4096, 1, 8192, 16385, 16384, 1, -32768, -65535, -65536, 1, 131072, 262145, 262144, 1, -524288, -1048575, -1048576, 1, 2097152, 4194305, 4194304, 1, -8388608, -16777215, -16777216, 1, 33554432 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Superseeker finds that a(n+2) - a(n) = A090131(n+1) (or with different signs, see A078069)

LINKS

Table of n, a(n) for n=0..50.

Index entries for linear recurrences with constant coefficients, signature (2,-1,-2,2).

FORMULA

a(n) = (1/2) [1 - (-1)^n - (1-I)^(n+1) - (1+I)^(n+1) ], with I=sqrt(-1). -- Ralf Stephan, Nov 16 2010

MATHEMATICA

CoefficientList[Series[(1-3x+x^2)/((x-1)(x+1)(2x^2-2x+1)), {x, 0, 60}], x] (* Harvey P. Dale, Mar 20 2013 *)

PROG

Floretion Algebra Multiplication Program, FAMP Code: 2ibaseiseq[ + .5'i + .5i' - .5'ii' + .5'jj' + .5'kk' + .5e]

CROSSREFS

Equals (1/2)[A010673(n)-A099087(n+2)].

Sequence in context: A100946 A200019 A282824 * A116516 A011417 A231890

Adjacent sequences:  A106661 A106662 A106663 * A106665 A106666 A106667

KEYWORD

easy,sign

AUTHOR

Creighton Dement, May 13 2005

STATUS

approved

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Last modified March 28 19:06 EDT 2017. Contains 284246 sequences.