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%I #20 Jun 07 2016 06:12:06
%S 2,17,3026,141457,4740625,113260225,205117028945,3234825286225
%N Least number of the form x^2 + y^4 in exactly n ways where x and y are nonzero integers.
%e a(1) = 2 = 1^2 + 1^4.
%e a(2) = 17 = 1^2 + 2^4 = 4^2 + 1^4.
%e a(3) = 3026 = 25^2 + 7^4 = 49^2 + 5^4 = 55^2 + 1^4.
%e a(4) = 141457 = 191^2 + 18^4 = 321^2 + 14^4 = 336^2 + 13^4 = 376^2 + 3^4.
%e a(5) = 4740625 = 2177^2 + 6^4 = 2175^2 + 10^4 = 1800^2 + 35^4 = 800^2 + 45^4 = 513^2 + 46^4.
%e a(6) = 113260225 = 10640^2 + 15^4 = 10593^2 + 32^4 = 10368^2 + 49^4 = 10015^2 + 60^4 = 7967^2 + 84^4 = 5640^2 + 95^4.
%o (PARI) do(lim,stride=10^7)=lim\=1;my(v,t,r,top);forstep(n=0,lim-1,stride,top=min(n+stride,lim);v=vectorsmall(top-n);for(y=1,sqrtnint(top-1,4),t=y^4;for(x=if(n>t,sqrtint(n-t)+1,1),sqrtint(top-t),v[t+x^2-n]++));for(i=1,#v,if(v[i]>r,r=v[i];print(r" "i+n)))) \\ _Charles R Greathouse IV_, Jun 07 2016
%Y Cf. A111925.
%K nonn,more
%O 1,1
%A _Altug Alkan_, Jun 06 2016
%E a(5)-a(6) from _Charles R Greathouse IV_, Jun 07 2016
%E a(7)-a(8) from _Giovanni Resta_, Jun 07 2016
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