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 A336123 a(1) = 0, a(2) = 1, and for n > 2, a(n) = [A122111(n) == 1 (mod 4)] + a(A253553(n)). 4
 0, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 3, 2, 1, 1, 1, 2, 2, 1, 1, 3, 1, 1, 2, 2, 1, 1, 1, 2, 3, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 1, 1, 3, 1, 1, 3, 3, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 2, 2, 2, 1, 1, 2, 4, 1, 1, 3, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 1, 3, 1, 1, 3, 2, 1, 1, 1, 2, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,8 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(1) = 0, a(2) = 1, and for n > 2, a(n) = [A336124(n) == 1] + a(A253553(n)). a(n) = A000120(A336125(n)). For n > 1, a(n) = A292375(A122111(n)). a(n) = A001222(n) - A336121(n). For all n >= 0, a(3^n) = n. PROG (PARI) \\ Uses also code given in A336124: A253553(n) = if(n<=2, 1, my(f=factor(n), k=#f~); if(f[k, 2]>1, f[k, 2]--, f[k, 1] = precprime(f[k, 1]-1)); factorback(f)); A336123(n) = if(n<=2, n-1, (1==A336124(n))+A336123(A253553(n))); CROSSREFS Cf. A000120, A000244, A001222, A122111, A292375, A336121, A336124, A336125. Sequence in context: A225518 A269972 A202205 * A353849 A075661 A206829 Adjacent sequences: A336120 A336121 A336122 * A336124 A336125 A336126 KEYWORD nonn AUTHOR Antti Karttunen, Jul 17 2020 STATUS approved

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Last modified October 2 04:44 EDT 2023. Contains 365831 sequences. (Running on oeis4.)