Gaussian Perfect number
y.kohmoto
zbi74583 at boat.zero.ad.jp
Mon Jan 10 06:46:18 CET 2005
Neil,
I post sequences of Gaussian PN to OEIS.
%I A000001
%S A000001 1, 5, 10, 10, 30, 30, 140, 200
%N A000001 Gaussian Perfect number.
Definition : GSigma(n)=m*n , for some Gaussian integer
m.
Where If n=Product p_i^r_i then GSigma(n)=Product (Sum
p_i^s_i, 0<=s_i<=r_i)
Sequence gives real part of Gaussian Perfect number.
%C A000001 The following condition is necessary for defining "Sum"
of Gaussian integer.
If a Gaussian integer is of the form : r*e^(i*t), then
0<=t<Pi/2.
GSigma(n) is a formal sum of divisors of n.
Indeed, sometimes it gives a kind of difference of
divisors of n.
%e A000001 GSigma((1+i)^7)=1+1+i+2+2+2*i+4+4+4*i+8+8+8*i=30+15*i
GSigma((1+i)*(2+i))=1+1+i+2+i+1+3i = 5+5i
=(1+i)*(2+i)*(1+2i) , so (1+i)*(2+i)=1+3i is a Gaussian Perfect number.
%Y A000001 A000002
%K A000001 nonn
%O A000001 1,2
%A A000001 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
%I A000002
%S A000002 3, 5, 10, 28, 30, 84, 140, 600
%N A000002 Gaussian Perfect number.
Definition : GSigma(n)=m*n , for some Gaussian integer
m.
Where If n=Product p_i^r_i then GSigma(n)=Product (Sum
p_i^s_i, 0<=s_i<=r_i)
Sequence gives imaginary part of Gaussian Perfect
number.
%C A000002 The following condition is necessary for defining "Sum"
of Gaussian integer.
If a Gaussian integer is of the form : r*e^(i*t),
then 0<=t<Pi/2.
GSigma(n) is a formal sum of divisors of n.
Indeed, sometimes it gives a kind of difference of
divisors of n.
%e A000002 GSigma((1+i)^7)=1+1+i+2+2+2*i+4+4+4*i+8+8+8*i=30+15*i
GSigma((1+i)*(2+i))=1+1+i+2+i+1+3i = 5+5i
=(1+i)*(2+i)*(1+2i) , so (1+i)*(2+i)=1+3i is a Gaussian Perfect number.
%Y A000002 A000001
%K A000002 nonn
%O A000002 1,1
%A A000002 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
%I A000003
%S A000003 1, 2, 3, 3, 4, 4, 4, 1
%N A000003 Real part of m number of Gaussian Perfect number
%Y A000003 A000001
%K A000003 nonn
%O A000003 1,2
%A A000003 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
%I A000004
%S A000004 2, 2, 3, 0, 4, 0, 4, 5,
%N A000004 Imaginary part of m number of Gaussian Perfect number
%Y A000004 A000001
%K A000004 nonn
%O A000004 1,1
%A A000004 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
I am not sure if the sequence is complete up to r=40^(1/2)*100.
I wish Farideh will do exhaustive search.
GSigma(n) is multiplicative, so this "Gaussian Perfect number" is
interesting..
But I want to know a formula for "true" sum of divisors of n.
Example :
n=(1+i)^2 * (1+2i)
GSigma(n)=(1+1+i+2) * (1+1+2i)= (4+i) * 2* (1+i)= 6+10i
If all divisors are described, then it becomes as follows.
GSigma(n)=1+1+i+2 + 1+2i-1+3i+2+4i=6+10i
The divisor " 3+i " is multiplied by the unit "i" , so it is a kind of
formal sum of divisors of n.
The "Sum" of divisors of n is the following.
TGSigma(n)=1+1+i+2 + 1+2i+3+i+2+4i= 10+8i
Where -1+3i == 3+i mod Pi/2
Yasutoshi
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