

A111866


Divide n! repeatedly by i! for i from floor(n/2) down through 2; a(n) = remaining quotient.


0



1, 1, 2, 6, 3, 15, 5, 35, 35, 105, 7, 77, 77, 1001, 143, 429, 2145, 36465, 12155, 230945, 46189, 323323, 29393, 676039, 676039, 16900975, 1300075, 2340135, 334305, 9694845, 215441, 6678671, 100180065, 3305942145, 64822395, 2268783825
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OFFSET

0,3


LINKS

Table of n, a(n) for n=0..35.


EXAMPLE

a(9): 9!/(4!*4!*3!) = 105.


MATHEMATICA

f[n_] := Block[{k = Floor[n/2], m = n!}, While[k > 1, While[ Mod[m, k! ] == 0, m /= k! ]; k ]; m]; Table[ f[n], {n, 0, 35}] (* Robert G. Wilson v *)


PROG

(PARI) a(n)=c=n!; forstep(d=floor(n/2), 2, 1, while (c%(d!)==0, c/=d!)); c


CROSSREFS

Cf. A055773.
Sequence in context: A094302 A094300 A055773 * A251753 A072155 A094299
Adjacent sequences: A111863 A111864 A111865 * A111867 A111868 A111869


KEYWORD

nonn


AUTHOR

Jon Perry, Nov 23 2005


EXTENSIONS

More terms from Robert G. Wilson v, Nov 25 2005


STATUS

approved



