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A081888 Numbers n such that the least positive primitive root of n is larger than the value for all positive numbers smaller than n. 3
1, 3, 4, 6, 22, 118, 191, 362, 842, 2042, 2342, 3622, 16022, 29642, 66602, 110881, 143522, 535802, 5070662, 6252122, 6497402, 10219442, 69069002 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A081889 gives the primitive roots itself. Difference from A002229, A002230: In consideration of all n having primitive roots. A002229, A002230 only primes.

LINKS

Table of n, a(n) for n=1..23.

FORMULA

Numbers 1, 2, 4, p^m and 2*p^m have primitive roots for odd primes p and m >=1 natural number.

MAPLE

a306252 := proc(n::integer)

    local r;

    r := numtheory[primroot](n) ;

    if r <> FAIL then

        return r ;

    else

        return -1 ;

    end if;

end proc:

A081888 := proc()

    local rec, n, lpr ;

    rec := -1 ;

    for n from 1 do

        lpr := a306252(n) ;

        if lpr > rec then

            printf("%d, \n", n) ;

            rec := lpr ;

        end if;

    end do:

end proc:

A081888() ; # R. J. Mathar, Apr 04 2019

CROSSREFS

Cf. A081889, A002229, A002230. Positions of records of A306252.

Sequence in context: A265735 A038520 A294990 * A306493 A019209 A019120

Adjacent sequences:  A081885 A081886 A081887 * A081889 A081890 A081891

KEYWORD

nonn,more

AUTHOR

Sven Simon, Mar 30 2003

STATUS

approved

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Last modified August 19 06:22 EDT 2022. Contains 356216 sequences. (Running on oeis4.)