A212842 Numbers expressible as sum of squares of two distinct positive triangular numbers exactly in two ways.

47125, 279225, 354061, 549181, 672409, 1626409, 3349125, 5504500, 6186250, 29811609, 32035636, 36082909, 66280609, 178651252, 265364325, 379845684, 380287441, 380367010, 385371234, 420373045, 526535109, 622542601, 654992101, 1065369601, 1298353716, 1339962850

Offset

1,1

Comments

Are there numbers expressible as T(m)^2 + T(n)^2 in exactly 3 (and more?) ways?

Links

Zak Seidov, Table of n, a(n) for n = 1..130

Example

47125 = T(14)^2 + T(19)^2 = 105^2 + 190^2, and
47125 = T(10)^2 + T(20)^2 = 55^2 + 210^2.

Crossrefs

Inspired by A212795.

Sequence in context: A250688 A183601 A206252 * A254549 A254556 A254479

Adjacent sequences: A212839 A212840 A212841 * A212843 A212844 A212845

Keyword

nonn

Author

Zak Seidov, May 28 2012

Status

approved