A260909 Denominator of 1/det(M) where M is the n X n matrix with M[i,j] = 1/gcd(i,j).

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 4, 4, 32, 2, 32, 32, 64, 64, 256, 256, 512, 128, 512, 1024, 2048, 1024, 4096, 16384, 32768, 1024, 4096, 32768, 262144, 131072, 524288, 524288, 4194304, 2097152, 16777216, 33554432, 67108864, 33554432, 268435456, 268435456

Offset

1,7

Comments

All terms are powers of two (A000079).

Links

Table of n, a(n) for n=1..46.

Maple

seq(denom(1/LinearAlgebra:-Determinant(Matrix(n, n, 1/igcd))), n=1..100); # Robert Israel, Aug 16 2015

Mathematica

f[n_] := 1/Det[ Table[ 1/GCD[i, j], {i, n}, {j, n}]]; Denominator@ Array[f, 46]

Prog

(PARI) vector(50, n, denominator(1/matdet(matrix(n, n, i, j, 1/gcd(i, j))))) \\ Michel Marcus, Aug 07 2015

Crossrefs

Cf. A000079, A260897, A260908.

Sequence in context: A158298 A009191 A229969 * A351945 A351943 A114717

Adjacent sequences: A260906 A260907 A260908 * A260910 A260911 A260912

Keyword

nonn

Author

Robert G. Wilson v, Aug 04 2015

Status

approved