Motzkin numbers: Difference between revisions
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Aside: <small>Note that, under 32-bit and p2js, M[36] and M[37] happen only by chance to be correct: an intermediate value exceeds precision (in this case for M[36] it is a multiple of 2 and hence ok, for M[37] it is rounded to the nearest multiple of 4, and the final divide by (i+1) results in an integer simply because there isn't enough precision to hold any fractional part).
Output as above on 64-bit, less four entries under 32-bit and pwa/p2js, since unlike M[36..37], M[38..41] don't quite get away with the precision loss, plus M[39] and above exceed precision and hence is_prime() limits on 32-bit anyway.</small>
=={{header|Python}}==
{{trans|Go}}
<syntaxhighlight lang="python">""" rosettacode.org/wiki/Motzkin_numbers """
from sympy import isprime
def motzkin(num_wanted):
""" Return list of the first N Motzkin numbers """
mot = [1] * (num_wanted + 1)
for i in range(2, num_wanted + 1):
mot[i] = (mot[i-1]*(2*i+1) + mot[i-2]*(3*i-3)) // (i + 2)
return mot
def print_motzkin_table(N=41):
""" Print table of first N Motzkin numbers, and note if prime """
print(
" n M[n] Prime?\n-----------------------------------")
for i, e in enumerate(motzkin(N)):
print(f'{i : 3}{e : 24,}', isprime(e))
print_motzkin_table()
</syntaxhighlight>{{out}} Same as Go example.
=={{header|Quackery}}==
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