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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 October 18 13:26 EDT 2019. Contains 328161 sequences. (Running on oeis4.)