A380301 Semiperimeter of the unique primitive Pythagorean triple whose inradius is the n-th odd prime and whose short leg is an even number.

20, 42, 72, 156, 210, 342, 420, 600, 930, 1056, 1482, 1806, 1980, 2352, 2970, 3660, 3906, 4692, 5256, 5550, 6480, 7140, 8190, 9702, 10506, 10920, 11772, 12210, 13110, 16512, 17556, 19182, 19740, 22650, 23256, 25122, 27060, 28392, 30450, 32580, 33306, 37056, 37830, 39402

Offset

0,1

References

Miguel Ángel Pérez García-Ortega, José Manuel Sánchez Muñoz and José Miguel Blanco Casado, El Libro de las Ternas Pitagóricas, Preprint 2025.

Links

Table of n, a(n) for n=0..43.

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

Formula

a(n) = ( A367335(n,1) + A367335(n,2) + A367335(n,3) )/2.

Mathematica

a = Table[Prime[n], {n, 2, 54}]; Apply[Join, Map[{#^2 + 3 # + 2} &, a]]

Crossrefs

Cf. A367335, A377016, A378380, A378965, A379506.

Sequence in context: A041796 A041798 A132762 * A075228 A256102 A128672

Adjacent sequences: A380298 A380299 A380300 * A380302 A380303 A380304

Keyword

nonn,easy

Author

Miguel-Ángel Pérez García-Ortega, Jan 19 2025

Status

approved