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A093378 a(n) = numerator of any non-diagonal entry of the matrix A^n, where A is described in the Comments lines. 1
2, 12, 22, 168, 1558, 5148, 8062, 177072, 860882, 738492, 121008888, 298775878, 1232566932, 14864798542, 58374617952 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A =

[ -(3/5)-(2/5)i,-(2/5)i,-(2/5)i,-(2/5)i ]

[ -(2/5)i,-(3/5)+(2/5)i,-(2/5)i,(2/5)i ]

[ -(2/5)i,-(2/5)i,-(3/5)+(2/5)i,(2/5)i ]

[ -(2/5)i,(2/5)i,(2/5)i,-(3/5)-(2/5)i ]

is the Cayley transform of the matrix iH, where H =

[1,1,1,1]

[1,-1,1,-1]

[1,1,-1,-1]

[1,-1,-1,1]

is an Hadamard matrix of order 4 and i is the imaginary unit.

LINKS

Table of n, a(n) for n=1..15.

CROSSREFS

Cf. A066771.

Sequence in context: A073211 A233137 A094626 * A012664 A012545 A009514

Adjacent sequences:  A093375 A093376 A093377 * A093379 A093380 A093381

KEYWORD

nonn,frac

AUTHOR

Simone Severini, Apr 28 2004

STATUS

approved

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Last modified September 23 13:55 EDT 2017. Contains 292358 sequences.