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A087601 Primes occurring as lesser side of Heronian triangle (sides are consecutive integers, area and inradius are integers). 1
3, 13, 193, 37633, 7300801, 1416317953 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term (if it exists) is greater than 10^10000. - Ray Chandler, Jul 04 2015

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.

LINKS

Table of n, a(n) for n=1..6.

FORMULA

Prime elements of A016064. Alternatively, primes p such that 3*(p+1)^2-12 is a square, i.e., p+1 belongs to A003500. - Max Alekseyev, May 14 2010

EXAMPLE

a(1)=3 because 3, 4 and 5 are sides of Heronian triangle (area is 6, inradius is 1).

CROSSREFS

Cf. A001353, A016064, A003500, A087602.

Sequence in context: A117808 A002065 A302143 * A145503 A112093 A085010

Adjacent sequences:  A087598 A087599 A087600 * A087602 A087603 A087604

KEYWORD

more,nonn

AUTHOR

Zak Seidov, Aug 07 2003

STATUS

approved

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Last modified May 24 04:25 EDT 2019. Contains 323528 sequences. (Running on oeis4.)