A070268 Numbers k such that mu(k) + mu(k+1) + mu(k+2) = -3.

29, 41, 101, 137, 229, 281, 429, 433, 617, 641, 645, 741, 821, 969, 1021, 1085, 1129, 1221, 1309, 1433, 1489, 1581, 1597, 1605, 1613, 1697, 1741, 1877, 1885, 2013, 2053, 2081, 2085, 2109, 2161, 2237, 2265, 2309, 2337, 2377, 2381, 2397, 2409, 2633, 2657, 2665, 2677

Offset: 1

Author

Sharon Sela (sharonsela(AT)hotmail.com), May 09 2002

Keywords

• nonn

Comments

All terms == 1 (mod 4). - Robert Israel, Feb 17 2019

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A008683 (mu), A063838.

Programs

Maple

with(numtheory): A070268:=n->`if`(mobius(n)+mobius(n+1)+mobius(n+2)=-3, n, NULL): seq(A070268(n), n=1..10^4); # Wesley Ivan Hurt, Feb 05 2017

Mathematica

seq[max_] := Module[{t = Table[MoebiusMu[n], {n, 1, max}]}, Flatten[Position[Partition[t, 3, 1], ?(Total[#] == -3 &)]]]; seq[2700] (* _Amiram Eldar, Jul 25 2025 *)

PARI

isok(n) = moebius(n)+moebius(n+1)+moebius(n+2)==-3;

Extensions

More terms from Benoit Cloitre, May 13 2002