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 A113793 Triangle T(n,m) read by rows: T(n,m) = phi(n - m + 1) * phi(m + 1). 0
 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 4, 2, 4, 2, 4, 2, 4, 4, 4, 4, 2, 6, 2, 8, 4, 8, 2, 6, 4, 6, 4, 8, 8, 4, 6, 4, 6, 4, 12, 4, 16, 4, 12, 4, 6, 4, 6, 8, 12, 8, 8, 12, 8, 6, 4, 10, 4, 12, 8, 24, 4, 24, 8, 12, 4, 10 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Row sums are 1, 2, 5, 8, 16, 20, 36, 44, 68, 76, 120, ... LINKS FORMULA T(n,m) = phi(n - m + 1) * phi(m + 1). EXAMPLE {1}, {1, 1}, {2, 1, 2}, {2, 2, 2, 2}, {4, 2, 4, 2, 4}, {2, 4, 4, 4, 4, 2}, {6, 2, 8, 4, 8, 2, 6}, {4, 6, 4, 8, 8, 4, 6, 4}, {6, 4, 12, 4, 16, 4, 12, 4, 6}, {4, 6, 8, 12, 8, 8, 12, 8, 6, 4}, {10, 4, 12, 8, 24, 4, 24, 8, 12, 4, 10} MATHEMATICA T[n_, m_] = EulerPhi[n - m + 1]*EulerPhi[m + 1]; Table[Table[T[n, m], {m, 0, n}], {n, 0, 10}]; Flatten[%] CROSSREFS Cf. A000010. Sequence in context: A025859 A031281 A203181 * A289499 A215904 A083552 Adjacent sequences:  A113790 A113791 A113792 * A113794 A113795 A113796 KEYWORD nonn,tabl AUTHOR Roger L. Bagula and Gary W. Adamson, Aug 25 2008 STATUS approved

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Last modified May 9 15:34 EDT 2021. Contains 343742 sequences. (Running on oeis4.)