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A133295 Smallest squarefree k such that the first n nonzero values of mu(j), j>=k, are all equal (mu is the Moebius function). 1
1, 2, 2, 91, 97, 201, 201, 598, 2683, 2683, 2683, 3090, 3090, 38401, 38401, 41226, 293037, 293037, 294574, 2156849, 4819826, 8812154, 10309514, 10309514, 10309514, 39479386, 476531349, 768912879, 1654065545, 5332819918, 8974545041, 16907435569, 17785220641 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..37

EXAMPLE

a(6)=201 because the first occurrence of 6 consecutive squarefree numbers with numbers of prime divisors having the same parity is 201, 202, 203, 205, 206, 209.

MATHEMATICA

f[n_] := Module[{c = 0, m = MoebiusMu[n]}, If[m == 0, Return[0]]; nn = n; mm = m; While[mm == 0 || mm == m, If[mm != 0, c++]; nn++; mm = MoebiusMu[nn]]; c]; mx = 19; v = Table[0, {mx}]; count = 0; Do[f1 = f[n]; Do[If[v[[j]] == 0, v[[j]] = n; count++], {j, 1, f1}]; If[count == mx, Break[]], {n, 1, 10^6}]; v (* Amiram Eldar, Aug 30 2019 *)

CROSSREFS

Cf. A005117, A008683.

Sequence in context: A191779 A156511 A166996 * A055470 A270591 A210467

Adjacent sequences:  A133292 A133293 A133294 * A133296 A133297 A133298

KEYWORD

nonn

AUTHOR

Michel Balazard (balazard(AT)math.u-bordeaux1.fr), Oct 17 2007, Oct 19 2007

EXTENSIONS

More terms from Amiram Eldar, Aug 30 2019

STATUS

approved

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Last modified May 20 08:03 EDT 2022. Contains 353852 sequences. (Running on oeis4.)