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A005094 Number of distinct primes of the form 4k+1 dividing n minus number of distinct primes of the form 4k+3 dividing n. 8
0, 0, -1, 0, 1, -1, -1, 0, -1, 1, -1, -1, 1, -1, 0, 0, 1, -1, -1, 1, -2, -1, -1, -1, 1, 1, -1, -1, 1, 0, -1, 0, -2, 1, 0, -1, 1, -1, 0, 1, 1, -2, -1, -1, 0, -1, -1, -1, -1, 1, 0, 1, 1, -1, 0, -1, -2, 1, -1, 0, 1, -1, -2, 0, 2, -2, -1, 1, -2, 0, -1, -1, 1, 1, 0, -1, -2, 0, -1, 1, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,21

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

FORMULA

Additive with a(p^e) = 0 if p = 2, 1 if p = 1 (mod 4), -1 if p = 3 (mod 4).

From Reinhard Zumkeller, Jan 07 2013: (Start)

a(n) = A005089(n) - A005091(n).

a(A221264(n)) < 0.

a(A078613(n)) = 0.

a(A221265(n)) > 0.

(End)

a(A267099(n)) = -a(n). - Antti Karttunen, Feb 03 2016

PROG

(Haskell)

a005094 n = a005089 n - a005091 n  -- Reinhard Zumkeller, Jan 07 2013

CROSSREFS

Cf. A005089, A005091, A078613, A221264, A221265, A267099.

Cf. A079635 (difference when counted with multiplicity).

Sequence in context: A037912 A056980 A268643 * A121372 A249351 A123706

Adjacent sequences:  A005091 A005092 A005093 * A005095 A005096 A005097

KEYWORD

sign

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More precise definition from Antti Karttunen, Feb 03 2016

STATUS

approved

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Last modified February 16 15:17 EST 2020. Contains 331961 sequences. (Running on oeis4.)