A284994 Floor(Gamma(n/2)).
1, 1, 0, 1, 1, 2, 3, 6, 11, 24, 52, 120, 287, 720, 1871, 5040, 14034, 40320, 119292, 362880, 1133278, 3628800, 11899423, 39916800, 136843365, 479001600, 1710542068, 6227020800, 23092317922, 87178291200, 334838609873, 1307674368000, 5189998453040
Offset: 1
Examples
Let s = sqrt(Pi); for n>=1, gamma(n/2) takes the values s, 1, s/2, 1, 3s/4, 2, 15s/8, 6, so that a(n) begins with 1,1,0,1,1,2,3,6.
Links
- Clark Kimberling, Table of n, a(n) for n = 1..500
Programs
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Mathematica
Table[Floor[Gamma[n/2]], {n, 1, 35}]
Formula
a(n) = floor(Gamma(n/2)).
Comments