A071859 - OEIS

A071859

Determinant of M_n where M_n is the n X n matrix m_(i,j) = A030300(i+j).

0, 0, -1, 1, 1, -1, 0, 0, 1, 1, -1, -1, 0, 0, -1, 1, 1, 1, -2, 2, 3, -3, -1, 1, -2, -2, 1, 1, 1, -1, 0, 0, 1, 1, -1, 1, 2, -2, -1, -1, 3, 3, -2, -2, -1, 1, -1, -1, 0, 0, 1, -1, -1, 1, 0, 0, 1, 1, -1, -1, 0, 0, -1, 1, 1, 1, -2, 2, 3, -3, -1, -1, 4, 4, -3, -3

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OFFSET

1,19

COMMENTS

a(n)=0 for n=1,2,7,8,13,14,31,32,49,50,55,56,61,62...hence if a(n)=0, n odd it seems that a(n+1)=0. It seems also that if a(n)=0 (n odd ) then n == 1 mod 6 (converse doesn't hold).

LINKS

Table of n, a(n) for n=1..76.

PROG

(PARI) for(n=1, 70, print1(matdet(matrix(n, n, i, j, length(binary(j+i))%2)), ", "))

CROSSREFS

Cf. A030300.

Sequence in context: A319772 A079729 A288723 * A135695 A105899 A071434

Adjacent sequences: A071856 A071857 A071858 * A071860 A071861 A071862

KEYWORD

easy,sign

AUTHOR

Benoit Cloitre, Jun 09 2002

EXTENSIONS

Name corrected by Nathaniel Johnston, Sep 26 2011

STATUS

approved