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A050452 a(n) = Sum_{d|n, d=3 mod 4} d. 12
0, 0, 3, 0, 0, 3, 7, 0, 3, 0, 11, 3, 0, 7, 18, 0, 0, 3, 19, 0, 10, 11, 23, 3, 0, 0, 30, 7, 0, 18, 31, 0, 14, 0, 42, 3, 0, 19, 42, 0, 0, 10, 43, 11, 18, 23, 47, 3, 7, 0, 54, 0, 0, 30, 66, 7, 22, 0, 59, 18, 0, 31, 73, 0, 0, 14, 67, 0, 26, 42, 71, 3, 0, 0, 93, 19, 18 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harvey P. Dale)

FORMULA

a(n) = A000593(n) - A050449(n). - Reinhard Zumkeller, Apr 18 2006

G.f.: Sum_{k>=1} (4*k - 1)*x^(4*k-1)/(1 - x^(4*k-1)). - Ilya Gutkovskiy, Mar 21 2017

MAPLE

A050452 := proc(n)

        a := 0 ;

        for d in numtheory[divisors](n) do

                if d mod 4 = 3 then

                        a := a+d ;

                end if;

        end do:

        a;

end proc:

seq(A050452(n), n=1..40) ; # R. J. Mathar, Dec 20 2011

MATHEMATICA

Table[Total[Select[Divisors[n], Mod[#, 4]==3&]], {n, 80}] (* Harvey P. Dale, Jul 07 2013 *)

CROSSREFS

Cf. A001842, A035462.

Cf. Sum_{d|n, d=k-1 mod k} d: A000593 (k=2), A078182 (k=3), this sequence (k=4).

Sequence in context: A285213 A285339 A005082 * A267875 A200517 A151665

Adjacent sequences:  A050449 A050450 A050451 * A050453 A050454 A050455

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 23 1999

STATUS

approved

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Last modified February 23 00:33 EST 2018. Contains 299473 sequences. (Running on oeis4.)