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 A110174 Number of solutions 0
 0, 0, 2, 1, 0, 0, 0, 1, 2, 2, 0, 1, 0, 4, 4, 1, 0, 2, 0, 5, 4, 4, 0, 3, 4, 4, 4, 7, 0, 0, 0, 1, 6, 2, 2, 3, 0, 6, 2, 7, 0, 2, 0, 9, 6, 4, 0, 3, 0, 4, 6, 9, 0, 4, 2, 9, 4, 2, 0, 1, 0, 4, 4, 1, 4, 4, 0, 9, 4, 4, 0, 5, 0, 4, 8, 9, 2, 6, 0, 7, 0, 2, 0, 3, 4, 4, 8, 9, 0, 2, 0, 11, 8, 4, 0, 3, 0, 2, 6, 9, 0, 6, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS MATHEMATICA a[n_] := Select[Range[n-1], EulerPhi[n]==EulerPhi[n-# ]+EulerPhi[ # ]&]; Table[Length[a[n]], {n, 150}] CROSSREFS Cf. A110173 (least k such that phi(n)=phi(k)+phi(n-k)). Sequence in context: A026821 A039964 A035172 * A022909 A292136 A032239 Adjacent sequences:  A110171 A110172 A110173 * A110175 A110176 A110177 KEYWORD nonn AUTHOR T. D. Noe, Jul 15 2005 STATUS approved

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Last modified January 15 18:52 EST 2019. Contains 319170 sequences. (Running on oeis4.)