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 A130208 Diagonalized matrix of A000203, Sigma(n). 5
 1, 0, 3, 0, 0, 4, 0, 0, 0, 7, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 12, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 15 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS A130207 replaces Sigma(n) with phi(n), A000010. A130209 replaces Sigma(n) with d(n), A000005. LINKS FORMULA Infinite lower triangular matrix with A000203, Sigma(n), in the main diagonal and the rest zeros. EXAMPLE First few rows of the triangle are: 1; 0, 3; 0, 0, 4; 0, 0, 0, 7; 0, 0, 0, 0, 6; 0, 0, 0, 0, 0, 12; ... PROG (PARI) for(n=1, 9, for(k=2, n, print1("0, ")); print1(sigma(n)", ")) \\ Charles R Greathouse IV, Feb 14 2013 CROSSREFS Cf. A000203, A130207, A130209. Sequence in context: A021773 A244126 A133109 * A288654 A259191 A240455 Adjacent sequences:  A130205 A130206 A130207 * A130209 A130210 A130211 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, May 16 2007 STATUS approved

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Last modified January 17 14:12 EST 2019. Contains 319225 sequences. (Running on oeis4.)