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A174647 Determinant of the matrix a(i,j) = 1 if Abs(i-j) <2 and -1 in the rest. 0
-4, 0, 0, 0, -64, 0, 256, 1024, 0, -4096, -12288, 0, 49152, 131072, 0, -524288, -1310720, 0, 5242880, 12582912, 0, -50331648, -117440512, 0, 469762048, 1073741824, 0, -4294967296, -9663676416, 0, 38654705664, 85899345920, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Table of n, a(n) for n=3..35.

FORMULA

Empirical g.f.: -4*x^3*(8*x^3+4*x^2-2*x+1) / ((2*x+1)*(4*x^2-2*x+1)^2). - Colin Barker, Jun 20 2013

EXAMPLE

Det({ {1, 1, -1, -1, -1, -1, -1}, {1, 1, 1, -1, -1, -1, -1}, {-1, 1, 1, 1, -1, -1, -1}, {-1, -1, 1, 1, 1, -1, -1}, {-1, -1, -1, 1, 1, 1, -1}, {-1, -1, -1, -1, 1, 1, 1}, {-1, -1, -1, -1, -1, 1, 1} }=-64 => a(7)=-64

CROSSREFS

Sequence in context: A057386 A099306 A228630 * A258644 A169770 A287633

Adjacent sequences:  A174644 A174645 A174646 * A174648 A174649 A174650

KEYWORD

sign

AUTHOR

José María Grau Ribas, Mar 25 2010

STATUS

approved

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Last modified January 23 01:48 EST 2020. Contains 331166 sequences. (Running on oeis4.)