A298467 Smallest positive integer that can be expressed as the sum of consecutive positive squares in exactly n ways.

1, 25, 20449, 554503705

Offset: 1

Author

Seiichi Manyama, Jan 19 2018

Keywords

• nonn
• more

Comments

a(5) > 10^9. - Rémy Sigrist, Jan 19 2018

a(5) > 10^15. - Michael S. Branicky, Feb 18 2023

Examples

			a(2) = 25 because 3^2 + 4^2 = 5^2 = 25,
a(3) = 20449 because 7^2 + 8^2 + ... + 39^2 = 38^2 + 39^2 + ... + 48^2 = 143^2 = 20449.
a(4) = 554503705 because 480^2 + 481^2 + ... + 1210^2 = 3570^2 + 3571^2 + ... + 3612^2 = 3613^2 + 3614^2 + ... + 3654^2 = 7442^2 + 7443^2 ... + 7451^2 = 554503705. - _Rémy Sigrist_, Jan 19 2018
		

Crossrefs

Cf. A038547, A111044, A130052, A234304, A234311.

Formula

a(n) <= A234311(n).

Extensions

a(4) from Rémy Sigrist, Jan 19 2018