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Intersection of A000330 and A086849.
0

%I #11 Jul 09 2022 15:36:29

%S 5,91,506,650,11440

%N Intersection of A000330 and A086849.

%C Numbers that are the sum of the first r nonsquares and also the sum of the first s squares for some r and s.

%C If it exists, a(6) > 5.4*10^12.

%C If it exists, a(6) > 10^20. - _Michael S. Branicky_, Jul 09 2022

%e 1+4+9+16+25+36 = 2+3+5+6+7+8+10+11+12+13+14 = 91, so 91 is a term.

%t a000330=Accumulate[Table[i^2,{i,60}]];

%t a086849=Accumulate[Table[i+Floor[1/2+Sqrt[i]],{i,370}]];

%t Intersection[a000330,a086849]

%Y Cf. A000330, A086849.

%K nonn,more

%O 1,1

%A _Ivan N. Ianakiev_, Jun 30 2022