A004733 Denominator of n!!/(n+3)!!.

3, 8, 15, 16, 105, 128, 315, 256, 3465, 1024, 9009, 2048, 45045, 32768, 109395, 65536, 2078505, 262144, 4849845, 524288, 22309287, 4194304, 50702925, 8388608, 456326325, 33554432, 1017958725, 67108864

Offset

0,1

References

S. Janson, On the traveling fly problem, Graph Theory Notes of New York, Vol. XXXI, 17, 1996.

Links

Table of n, a(n) for n=0..27.

S. Janson, On the traveling fly problem.

Prog

(PARI) a(n) = denominator(prod(i=0, floor((n-1)/2), n-2*i)/prod(i=0, floor((n+2)/2), n+3-2*i)) \\ Michel Marcus, May 24 2013

Crossrefs

Cf. A004732.

Cf. A001801.

Sequence in context: A135872 A242245 A045263 * A310307 A051210 A191773

Adjacent sequences: A004730 A004731 A004732 * A004734 A004735 A004736

Keyword

nonn,frac

Author

N. J. A. Sloane

Status

approved