A087602 Primes occurring as larger side of Heronian triangle (sides are consecutive integers, area and inradius are integers).
3, 5, 53, 140453
Offset: 1
Examples
a(3)=53 because 53, 52 and 51 are sides of Heronian triangle (area is 1170, inradius is 15).
References
- Mohammad K. Azarian, Circumradius and Inradius, Problem S125, Math Horizons, Vol. 15, Issue 4, April 2008, p. 32. Solution published in Vol. 16, Issue 2, November 2008, p. 32.
Formula
p, p-1 and p-2 are sides of Heronian triangle.
Primes p such that 3*(p-1)^2-12 is a square, i.e., p-1 belongs to A003500. - Max Alekseyev, May 14 2010
Comments