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A118713 a(n) = determinant of n X n circulant matrix whose first row is A001358(1), A001358(2), ..., A001358(n) where A001358(n) = n-th semiprime. 8
4, -20, 361, -3567, 218053, -3455872, 736439027, -16245418225, 1519211613654, -37662452460912, 20199655476042865, -643524421698841536, 46513669467992431114 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Semiprime analogue of A066933 Circulant of prime numbers. a(n) alternates in sign. A048954 Wendt determinant of n-th circulant matrix C(n). A052182 Circulant of natural numbers. A086459 Circulant of powers of 2.

LINKS

Eric Weisstein's World of Mathematics, Circulant Matrix.

EXAMPLE

a(2) = -20 = determinant

|4,6|

|6,4|.

a(3) = 361 = 19^2 = determinant

|4,6,9|

|9,4,6|

|6,9,4|.

MAPLE

A118713 := proc(n)

    local C, r, c ;

    C := Matrix(1..n, 1..n) ;

    for r from 1 to n do

    for c from 1 to n do

        C[r, c] := A001358(1+((c-r) mod n)) ;

    end do:

    end do:

    LinearAlgebra[Determinant](C) ;

end proc:

seq(A118713(n), n=1..13) ;

CROSSREFS

Cf. A001358, A048954, A052182, A066933, A086459, A086569.

Sequence in context: A012797 A167002 A054465 * A160703 A132511 A144989

Adjacent sequences:  A118710 A118711 A118712 * A118714 A118715 A118716

KEYWORD

easy,sign

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), May 20 2006

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com) at the suggestion of Andrew Plewe, Aug 23 2007

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.