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 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, 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 (list; graph; refs; listen; history; text; internal format)
 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

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Last modified September 12 07:34 EDT 2024. Contains 375842 sequences. (Running on oeis4.)