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 A063838 Numbers n such that mu(n) + mu(n+1) + mu(n+2) = 3. 10
 33, 85, 93, 141, 201, 213, 217, 301, 393, 445, 633, 697, 869, 921, 1041, 1137, 1189, 1253, 1261, 1345, 1401, 1589, 1641, 1761, 1793, 1837, 1893, 1937, 1941, 1981, 2045, 2101, 2181, 2189, 2217, 2305, 2361, 2433, 2461, 2469, 2489, 2517, 2561, 2641, 2721 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES I. Niven and H. S. Zuckerman, An Introduction to the Theory of Numbers. 4th ed., Wiley, NY, 1980, p. 113. LINKS Harry J. Smith and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 1000 terms from Smith) MATHEMATICA Transpose[ Select[ Partition[ Range[ 3000 ], 3, 1 ], MoebiusMu[ #[ [ 1 ] ] ]+MoebiusMu[ #[ [ 2 ] ] ]+MoebiusMu[ #[ [ 3 ] ] ]==3& ] ][ [ 1 ] ] PROG (PARI) M(n) = moebius(n)+moebius(n+1)+moebius(n+2); j=[]; for(n=1, 5000, if(M(n)==3, j=concat(j, n))); j (PARI) M(n) = moebius(n) + moebius(n + 1) + moebius(n + 2) n=0; for (m=1, 10^9, if(M(m)==3, write("b063838.txt", n++, " ", m); if (n==1000, break))) \\ Harry J. Smith, Sep 01 2009 (PARI) list(lim)=my(v=List(), run, last); forsquarefree(k=33, lim\1+2, if(moebius(k)==1, if(k[1]-last==1, if(run++>2, listput(v, k[1]-2)), run=1); last=k[1], last=run=0)); Vec(v) \\ Charles R Greathouse IV, Jan 08 2018 CROSSREFS Cf. A008683. A proper subset of A007675. Sequence in context: A073251 A005238 A052214 * A075039 A039833 A250732 Adjacent sequences:  A063835 A063836 A063837 * A063839 A063840 A063841 KEYWORD easy,nonn AUTHOR Jason Earls, Aug 21 2001 STATUS approved

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Last modified September 18 04:14 EDT 2020. Contains 337165 sequences. (Running on oeis4.)