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Smallest number that is the sum of four positive n-th powers in three ways.
1

%I #13 Apr 11 2021 00:00:54

%S 28,1225,16578,1479604544,1885800643779

%N Smallest number that is the sum of four positive n-th powers in three ways.

%H R. Alter, <a href="https://doi.org/10.1007/BFb0096461">Computations and generalizations on a remark of Ramanujan</a>, pp. 182-196 of "Analytic Number Theory (Philadelphia, 1980)", ed. M. I. Knopp, Lect. Notes Math., Vol. 899, 1981.

%e a(2) = 28 = 1+1+1+25 = 4+4+4+16 = 1+9+9+9.

%Y Cf. A230563, A342893-A342903.

%K nonn,more

%O 2,1

%A _N. J. A. Sloane_, Apr 04 2021

%E a(5)-a(6) from _Jinyuan Wang_, Apr 10 2021