Search: id:A124980
Results 1-1 of 1 results found.

%I A124980
%S A124980 1,25,325,1105,4225,5525,203125,27625,71825,138125
%N A124980 Smallest strictly positive number decomposable in n different ways as 
               a sum of two squares.
%F A124980 a(3)=325 3-th term 325 is decomposable on 3 ways: 15^2+10^2 = 17^2+6^2 
               = 18^2+1^2
%F A124980 a(n)=A000446(n), n>1. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Jun 15 2008
%o A124980 (PARI) cnt2sqr(n)={local(cnt=0,y2) ; for(x=0,floor(sqrt(n)), y2=n-x^2 
               ; if( y2>=x^2 && issquare(y2), cnt++ ; ) ; ) ; return(cnt) ; } A124980(n)= 
               { local(a=1) ; while(1, if( cnt2sqr(a)==n, return(a) ; ) ; a++ ; 
               ) ; } { for(n=1,100, print(n," ",A124980(n)) ; ) ; } - R. J. Mathar 
               (mathar(AT)strw.leidenuniv.nl), Nov 29 2006
%Y A124980 Cf. A118882.
%Y A124980 Sequence in context: A020233 A020319 A000448 this_sequence A000446 A079875 
               A010977
%Y A124980 Adjacent sequences: A124977 A124978 A124979 this_sequence A124981 A124982 
               A124983
%K A124980 nonn
%O A124980 1,2
%A A124980 Artur Jasinski (grafix(AT)csl.pl), Nov 15 2006
%E A124980 More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 29 2006

Search completed in 0.001 seconds