A063848 Numbers k such that mu(k) + mu(k+1) + mu(k+2) = 2.

14, 20, 32, 34, 38, 55, 56, 84, 86, 91, 92, 94, 117, 118, 121, 122, 132, 133, 140, 142, 143, 144, 145, 158, 159, 176, 183, 200, 202, 203, 204, 205, 208, 212, 214, 215, 216, 218, 219, 235, 247, 252, 297, 298, 299, 300, 302, 303, 319, 325, 326, 327, 328, 333

Offset: 1

Author

Jason Earls, Aug 26 2001

Keywords

• easy
• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A063838.

Programs

Mathematica

Flatten[Position[Partition[MoebiusMu[Range[350]],3,1],?(Total[#]==2&),{1},Heads->False]] (* _Harvey P. Dale, Nov 26 2015 *)

PARI

m(n) = moebius(n)+moebius(n+1)+moebius(n+2);
j=[]; for(n=1,1000, if(m(n)==2,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)==2, write("b063848.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 01 2009