A383251 Short leg of the unique primitive Pythagorean triple whose inradius is A000108(n) and such that its long leg and its hypotenuse are consecutive natural numbers.

3, 3, 5, 11, 29, 85, 265, 859, 2861, 9725, 33593, 117573, 416025, 1485801, 5348881, 19389691, 70715341, 259289581, 955277401, 3534526381, 13128240841, 48932534041, 182965127281, 686119227301, 2579808294649, 9723892802905, 36734706144305, 139067101832009

Offset

0,1

Links

Table of n, a(n) for n=0..27.

Miguel-Ángel Pérez García-Ortega, El Libro de las Ternas Pitagóricas

Formula

a(n) = 2 * A000108(n) + 1.

Example

Triangles begin:
  n=0:      3,    4,    5;
  n=1:      3,    4,    5;
  n=2:      5,   12,   13;
  n=3:     11,   60,   61;
  ...
This sequences gives the first column.

Crossrefs

Cf. A000108 (inradius), A382114 (semiperimeter), A381483 (area), A386291 (long legs).

Sequence in context: A191632 A146918 A093306 * A093309 A187874 A126318

Adjacent sequences: A383248 A383249 A383250 * A383252 A383253 A383254

Keyword

nonn,easy

Author

Miguel-Ángel Pérez García-Ortega, Apr 20 2025

Status

approved