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A221281 Numbers n such that lambda(n) = lambda(n+1) = lambda(n+2), where lambda(n) = A008836(n) is the Liouville function. 3
11, 14, 17, 18, 24, 27, 28, 29, 30, 33, 34, 38, 41, 42, 43, 54, 55, 56, 66, 70, 71, 78, 84, 85, 86, 93, 94, 97, 101, 107, 108, 112, 121, 132, 133, 134, 137, 140, 141, 142, 143, 144, 147, 158, 159, 162, 163, 170, 171, 172, 173, 174, 179, 180, 183, 190, 191, 201, 202, 203, 204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Hildebrand proved that this sequence is infinite. More generally, he showed that the eight values (1, 1, 1), (1, 1, -1), ..., (-1, -1, -1) each appear infinitely often as consecutive values of the Liouville function.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Adolf Hildebrand, On consecutive values of the Liouville function, Enseign. Math. (2) 32 (1986), no. 3-4, pp. 219-226.

MATHEMATICA

SequencePosition[LiouvilleLambda[Range[250]], {x_, x_, x_}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 16 2021 *)

PROG

(PARI) is(n)=my(k=(-1)^bigomega(n)); k==(-1)^bigomega(n+1) && k==(-1)^bigomega(n+2)

CROSSREFS

Subsequence of A221280. Cf. A008836, A221282.

Sequence in context: A038630 A239935 A219179 * A025058 A025060 A093669

Adjacent sequences:  A221278 A221279 A221280 * A221282 A221283 A221284

KEYWORD

nonn,changed

AUTHOR

Charles R Greathouse IV, Jan 09 2013

STATUS

approved

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Last modified June 16 13:05 EDT 2021. Contains 345057 sequences. (Running on oeis4.)