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A255132
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Number of divisors of odd Catalan numbers (A038003).
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2
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1, 1, 2, 8, 96, 2048, 3145728, 206158430208, 27670116110564327424, 498460498419343452338927647605129216, 24991100464315816765228594460089760794425300959309994174606999552, 336610107623104398583024455855523763248864803845734108839073897168302318415095310965480469919661369165797247714066432
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OFFSET
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0,3
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LINKS
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FORMULA
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EXAMPLE
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A038003(4) = 9694845 which has 96 divisors.
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PROG
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(Python)
from operator import mul
from functools import reduce
from sympy import factorint
for n in range(2, 2**15):
....for p, e in factorint(4*n-2).items():
........if p in c:
............c[p] += e
........else:
............c[p] = e
....for p, e in factorint(n+1).items():
........if c[p] == e:
............del c[p]
........else:
............c[p] -= e
....if n == s:
........c2 = reduce(mul, [e+1 for e in c.values()])
........s = 2*s+1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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