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A071534
Determinant of n X n matrix of form : [1 2 1 0 0 0 0 0 0 0 / 2 1 2 1 0 0 0 0 0 0 / 1 2 1 2 1 0 0 0 0 0 / 0 1 2 1 2 1 0 0 0 0 / 0 0 1 2 1 2 1 0 0 0 / 0 0 0 1 2 1 2 1 0 0 / 0 0 0 0 1 2 1 2 1 0 / 0 0 0 0 0 1 2 1 2 1 / 0 0 0 0 0 0 1 2 1 2 / 0 0 0 0 0 0 0 1 2 1].
1
1, -3, 0, 12, -8, -35, 57, 81, -264, -80, 1000, -495, -3159, 4221, 7912, -21140, -11568, 83997, -24495, -278783, 304336, 751296, -1665360, -1365375, 6971185, -595619, -24258384, 21035052, 69622920, -128909123, -146359223, 571337745, 73385352, -2083467984, 1364948056, 6324200785
OFFSET
1,2
LINKS
J. Borowska, L. Lacinska, Recurrence form of determinant of a heptadiagonal symmetric Toeplitz matrix, J. Appl. Math. Comp. Mech. 13 (2014) 19-16, remark 1 a=c=1, b=2.
FORMULA
G.f.: -x*(1-3*x+x^4+3*x^2) / ( (x-1)*(x^4+x^3+4*x^2+x+1) ).
PROG
(PARI) x=1; y=2; z=1; for(n=1, 80, print1(matdet(matrix(n, n, i, j, if(abs(i-j)-1, 0, y)+if(abs(i-j)-2, 0, z)+if(abs(i-j), 0, x))), ", "))
CROSSREFS
Sequence in context: A055314 A110890 A249010 * A336667 A269880 A135687
KEYWORD
easy,sign
AUTHOR
Benoit Cloitre, Jun 20 2002
STATUS
approved