Bug in apell?

[John Cremona <John.Cremona@nottingham.ac.uk>]

The code

e=ellinit([0, 460397952, 0, 275613539, 0],1)
q=1185848623
ellap(e,q)

does not return a value after a long time (on either a 32 or a 64 bit
machine).  The next prime q=1185848627 returns a value (67460)
instantly.

This came up in the middle of a big run where millions of curves had
their points counted (literally), and this is the only example which
caused a problem.

Any ideas where the problem lies?  According to magma the correct answer
(for the problem prime 1185848623) is -36184, and the group order is
1185884808 = (2^3)*(3)*(49411867).

John

-- 
 Prof. J. E. Cremona             |
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