A355371 Intersection of A000330 and A086849.

5, 91, 506, 650, 11440

Offset

1,1

Comments

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

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

If it exists, a(6) > 10^20. - Michael S. Branicky, Jul 09 2022

Links

Table of n, a(n) for n=1..5.

Example

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

Mathematica

a000330=Accumulate[Table[i^2, {i, 60}]];
a086849=Accumulate[Table[i+Floor[1/2+Sqrt[i]], {i, 370}]];
Intersection[a000330, a086849]

Crossrefs

Cf. A000330, A086849.

Sequence in context: A038636 A282052 A152299 * A242945 A243198 A091281

Adjacent sequences: A355368 A355369 A355370 * A355372 A355373 A355374

Keyword

nonn,more

Author

Ivan N. Ianakiev, Jun 30 2022

Status

approved