Amicable m-ple
koh
zbi74583 at boat.zero.ad.jp
Thu Dec 21 08:01:13 CET 2006
Hi, Seqfans
I considered about sequences of the smallest members of m-multiple Perfect Number and Amicable m-ple and 1/2-Amicable 2*m-ple.
The definitions are as follows.
m-PN : Sigma(n)=m*n
A m-ple : Sigma(n_i)=Sum_{1<=i<=m} n_i , 1<=i<=m
1/2-A 2*m-ple : Sigma(n_i)=1/2*(Sum_{1<=i<=2*m} n_i) ,1<=i<=2*m
If for all i n_i = n then these definitions becomes the same, so I supposed that the sizes of m-PN and A m-ple and 1/2-A 2*mple are almost the same.
But it doesn't seem to be correct. .
Between their sizes, some relationship might exist.
The smallest examples of m-PN and A m-ple and 1/2-A 2*m-ple are as follows.
m PN A m-ple 1/2-A 2*m-ple
1 1 1 no
2 2 220 32 digits kn
3 120 1980 60681331968409600 kn
4 30240 3270960 174547933583278080 kn
5 14182439040 22749116458844160 kn un
6 21 digits un un
7 57 digits un un
8 133 digits un un
9 287 digits un un
10 685 digits un un
11 1907 digits un un
Where "un" means "unknown", "kn" means "known the smallest".
%S A000001 1,2,120,30240,14182439040
%N A000001 The smallest m-multiple Perfect Number.
%S A000002 1,220,1980,3270960, 22749116458844160
%N A000002 The smallest member of the smallest Amicable m-ple.
%C A000002 There is no proof that (227491164588441600, 228507506351308800, 229862628701798400, 230878970464665600,243752632794316800) is the smallest Amicable Quintuple.
%S A000003 5702524371272605100551486698903,60681331968409600, 174547933583278080
%N A000003 The smallest member of the smallest 1/2-Amicable 2*m-ple.
%C A000003 The first term must be much smaller than this example.
A000001 already exists on OEIS.
I will submit A000002.
I am not sure if A000003 fits to OEIS.
Yasutoshi
More information about the SeqFan
mailing list