OFFSET
0,3
COMMENTS
When is next nonzero value, for n>11?
EXAMPLE
a(3) = 0 because for instance, first row = 3rd row = (1,2,2).
a(6) = 0 because for instance, 3rd column = 6th column = (2,2,2,2,2,2).
a(7) = 0 because for instance, first column = 4th column.
a(9) = 0 because for instance, 9th column = 2 * 4th column.
MAPLE
From R. J. Mathar, Oct 15 2010: (Start)
read("transforms3") ; L := BFILETOLIST("b000002.txt") ;
for s from 1 to floor(sqrt(nops(L))) do m := Matrix(1..s, 1..s) ; for r from 0 to s-1 do for c from 0 to s-1 do m[r+1, c+1] := op(1+c+r*s, L) ; end do: end do: printf("%a, \n", LinearAlgebra[Determinant](m) ) ; end do: (End)
MATHEMATICA
nmax = 56; a2 = {1, 2, 2}; Do[ a2 = Join[a2, {1 + Mod[n-1, 2]}], {n, 3, nmax^2}, {a2[[n]]}]; a[0] = 0; a[n_] := Det[ Partition[ Take[a2, n^2], n]]; Table[a[n], {n, 0, nmax}] (* Jean-François Alcover, Jun 18 2013 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Jonathan Vos Post, May 25 2006
EXTENSIONS
More terms from R. J. Mathar, Oct 15 2010
STATUS
editing