(1)解:∵4Sn=
+2an+1,
a
∴当n≥2时,4Sn?1=
+2an?1+1.
a
两式相减得4an=
?
a
+2an?2an?1,
a
∴(an+an-1)(an-an-1-2)=0
∵an>0,∴an-an-1=2,
又4S1=
+2a1+1,∴a1=1
a
∴{an}是以a1=1为首项,d=2为公差的等差数列.
∴an=a1+(n-1)d=2n-1;
(2)解:由(1)知Sn=
=n2,(1+2n?1)n 2
假设正整数k满足条件,
则(k2)2=[2(k+2048)-1]2
∴k2=2(k+2048)-1,
解得k=65;
(3)证明:由Sn=n2得:Sm=m2,Sk=k2,Sp=p2
于是
+1 Sm
?1 Sp
=2 Sk
+1 m2
?1 p2
=2 k2
k2(p2+m2)?2m2p2
m2p2k2
∵m、k、p∈N*,m+p=2k,
∴
k2(p2+m2)?2m2p2
m2p