Search: id:A161992
Results 1-1 of 1 results found.

%I A161992
%S A161992 7,9,11,13,14,15,17,18,19,21,22,23,25,26,27,28,29,30,31,33,34,35,36,37,
%T A161992 38,39,41,42,43,44,45,46,47,49,50,51,52,53,54,55,56,57,58,59,60,61,62,
%U A161992 63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87
%N A161992 Numbers which squared are a sum of 3 distinct non-zero squares.
%C A161992 Square roots of squares in A004432. - R. J. Mathar, Sep 22 2009
%e A161992 7^2=2^2+3^2+6^2. 9^2=1^2+4^2+8^2. 11^2 = 2^2+6^2+9^2. 15^2=2^2+5^2+14^2.
%p A161992 isA004432 := proc(n) local x,y,z2 ; for x from 1 do if x^2 > n then break; 
               fi; for y from 1 to x-1 do z2 := n-x^2-y^2 ; if z2 < y^2 and z2 > 
               0 then if issqr(z2) then RETURN(true) ; fi; fi; od: od: false ; end:
%p A161992 isA161992 := proc(n) isA004432(n^2) ; end:
%p A161992 for n from 1 do if isA161992(n) then printf("%d\n",n) ; fi; od: # R. 
               J. Mathar, Sep 22 2009
%t A161992 lst={};Do[Do[Do[a=(x^2+y^2+z^2)^(1/2);If[a==IntegerPart[a],AppendTo[lst, 
               a]],{z,y+1,2*5!}],{y,x+1,2*5!}],{x,5!}];lst;q=Take[Union[%],150]
%Y A161992 Cf. A029747
%Y A161992 Sequence in context: A058483 A162308 A108815 this_sequence A167377 A004169 
               A066669
%Y A161992 Adjacent sequences: A161989 A161990 A161991 this_sequence A161993 A161994 
               A161995
%K A161992 nonn
%O A161992 1,1
%A A161992 Vladimir Orlovsky (4vladimir(AT)gmail.com), Jun 24 2009
%E A161992 Definition rephrased by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Sep 22 2009

Search completed in 0.001 seconds