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A065000 Numbers k such that Sum_{i=1..k} mu(sigma(i)) = 0. 1
2, 3, 5, 6, 7, 9, 10, 11, 12, 16, 17, 20, 21, 22, 23, 24, 61, 62, 63, 673, 674, 675, 725, 726, 727, 728, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742, 743, 744, 745, 784, 785, 786, 787, 788, 789, 790, 791, 792, 793, 797, 798, 799, 800, 801, 802, 803, 804 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

Position[Accumulate[MoebiusMu[DivisorSigma[1, Range[1000]]]], 0]//Flatten (* Harvey P. Dale, Aug 15 2016 *)

PROG

(PARI) { n=s=0; for (m=1, 10^9, s+=moebius(sigma(m)); if (s==0, write("b065000.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Oct 03 2009

CROSSREFS

Sequence in context: A136432 A039105 A187328 * A188292 A171948 A287527

Adjacent sequences:  A064997 A064998 A064999 * A065001 A065002 A065003

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Feb 19 2002

STATUS

approved

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Last modified January 18 13:38 EST 2022. Contains 350455 sequences. (Running on oeis4.)