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A172354
n such that the Moebius function take successively, from n, the values -1,0,-1,0,-1,0.
3
195, 1491, 1547, 1947, 2139, 2715, 2749, 2751, 2847, 2967, 3359, 3615, 3819, 4011, 4013, 4015, 4047, 4155, 4547, 5019, 5449, 5647, 5741, 5779, 6351, 6353, 6355, 6447, 6547, 6563, 6565, 6567, 6947, 6959, 6961, 6963, 7347, 7503, 7545, 7683, 8007, 9339, 10091
OFFSET
1,1
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 826.
G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 5th ed., Oxford Univ. Press, 1979, th. 262 and 287.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Marc Deléglise and Joël Rivat, Computing the summation of the Mobius function, Experiment. Math. 5:4 (1996), pp. 291-295.
G. Villemin's Almanac of Numbers, Nombres de Moebius et de Mertens
MAPLE
with(numtheory): for n from 1 to 15000 do; if mobius(n)= -1 and mobius(n+1) = 0 and mobius(n+2)= -1 and mobius(n+3)= 0 and mobius(n+4)= -1 and mobius(n+5) = 0 then print(n); else fi ; od;
MATHEMATICA
SequencePosition[MoebiusMu[Range[11000]], {-1, 0, -1, 0, -1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 17 2016 *)
PROG
(PARI) is(n)=moebius(n)<0 && !moebius(n+1) && moebius(n+2)<0 && !moebius(n+3) && moebius(n+4)<0 && !moebius(n+5) \\ Charles R Greathouse IV, Sep 26 2013
CROSSREFS
Moebius (or Möbius) function mu(n): A008683, A007423, A002321, A002996.
Sequence in context: A157239 A158003 A225713 * A295130 A257765 A259694
KEYWORD
nonn
AUTHOR
Michel Lagneau, Feb 01 2010
EXTENSIONS
a(4) inserted by Charles R Greathouse IV, Sep 26 2013
STATUS
approved