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A055029 Number of inequivalent Gaussian primes of norm n. +0
13
0, 0, 1, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0 (list; graph; listen)
OFFSET

0,6

COMMENT

These are the primes in the ring of integers a+bi, a and b rational integers, i = sqrt(-1).

Two primes are considered equivalent if they differ by multiplication by a unit (+-1, +-i).

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, A16.

L. W. Reid, The Elements of the Theory of Algebraic Numbers, MacMillan, NY, 1910, see Chap. V.

LINKS

Index entries for Gaussian integers and primes

FORMULA

a(n) = 2 if n is a prime = 1 (mod 4); a(n) = 1 if n is 2, or p^2 where p is a prime = 3 (mod 4); a(n) = 0 otherwise. - Frank Adams-Watters (FrankTAW(AT)Netscape.net), May 05 2006

EXAMPLE

There are 8 Gaussian primes of norm 5, +-1+-2i and +-2+-i, but only two inequivalent ones (2+-i).

CROSSREFS

Cf. A055025-A055028, A055664-...

Sequence in context: A056170 A059483 A067618 this_sequence A126812 A008442 A086076

Adjacent sequences: A055026 A055027 A055028 this_sequence A055030 A055031 A055032

KEYWORD

nonn,easy,nice

AUTHOR

njas, Jun 09 2000

EXTENSIONS

More terms from Reiner Martin (reinermartin(AT)hotmail.com), Jul 20 2001

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.


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