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A107924 Even numbers n such that n^2 is an arithmetic number. 4
296, 536, 632, 872, 1208, 1304, 1544, 2072, 2216, 2648, 2984, 3584, 3656, 3752, 3848, 3896, 3904, 3992, 4328, 4424, 4568, 4904, 5624, 5672, 5912, 6008, 6104, 6584, 6968, 7016, 7256, 7352, 7928, 8216, 8264, 8456, 8696, 8896, 8936, 9032, 9128, 9176, 9368 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Odd numbers with this property are much more numerous, cf. A107925, A003601 (arithmetic number).

LINKS

R. J. Mathar, Michael De Vlieger, Table of n, a(n) for n = 1..10778 (first 443 terms from R. J. Mathar)

MAPLE

isA107924 := proc(n)

    if type(n, 'even') then

        dvs := numtheory[divisors](n^2) ;

        add(d, d=dvs)/nops(dvs) ;

        if type(%, 'integer') then

            true;

        else

            false;

        end if;

    else

        false;

    end if;

end proc:

n := 1 :

for k from 2 to 100000 do

    if isA107924(k) then

        printf("%d %d\n", n, k) ;

        n := n+1 ;

    end if;

end do: # create b-file, R. J. Mathar, Jul 28 2014

MATHEMATICA

Select[Range[2, 10000, 2], Mod[DivisorSigma[1, #^2], DivisorSigma[0, #^2]]==0&]

CROSSREFS

Cf. A003601, A107925.

Sequence in context: A238512 A003780 A206339 * A224170 A223861 A223984

Adjacent sequences:  A107921 A107922 A107923 * A107925 A107926 A107927

KEYWORD

nonn,easy

AUTHOR

Zak Seidov, Jun 10 2005

STATUS

approved

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Last modified April 22 21:39 EDT 2018. Contains 302916 sequences. (Running on oeis4.)