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A070016 Least m such that Chowla's function value of m [A048050(m)] equals n or 0 if no such number exists. 2
0, 4, 9, 0, 6, 8, 10, 15, 14, 21, 121, 27, 22, 16, 12, 39, 289, 65, 34, 18, 20, 57, 529, 95, 46, 69, 28, 115, 841, 32, 58, 45, 62, 93, 24, 155, 1369, 217, 44, 63, 30, 50, 82, 123, 52, 129, 2209, 75, 40, 141, 0, 235, 42, 36, 106, 99, 68, 265, 3481, 371, 118, 64, 56, 117 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Remark that A070016(n)=A070015(n+1) in accordance with A048995(k)+1=A005114(k).

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n)=Min{x; A048050(x)=n} or a(n)=0 if n is from A048995.

EXAMPLE

n=127: a(n)=16129, divisors={1,127,16129}, 127=sigma[n]-n-1=127 and 16129 is the smallest.

MATHEMATICA

f1[x_] := DivisorSigma[1, x]-x-1; t=Table[0, {128}]; Do[b=f1[n]; If[b<129&&t[[b]]==0, t[[b]]=n], {n, 1, 1000000}]; t

CROSSREFS

Cf. A000203, A001065, A048050, A051444, A007369, A070016, A005114, A048995.

Sequence in context: A021675 A093872 A097906 * A243372 A020802 A085675

Adjacent sequences:  A070013 A070014 A070015 * A070017 A070018 A070019

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 12 2002

STATUS

approved

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Last modified April 7 07:50 EDT 2020. Contains 333292 sequences. (Running on oeis4.)