

A192676


FloorSqrt transform of derangement numbers (A000166).


0



1, 0, 1, 1, 3, 6, 16, 43, 121, 365, 1155, 3832, 13274, 47862, 179084, 693589, 2774358, 11438972, 48531450, 211543687, 946052129, 4335355493, 20334619731, 97521410321, 477755388567, 2388776942837, 12180420245150, 63291320166423, 334906186618646, 1803525009870353
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OFFSET

0,5


LINKS

Table of n, a(n) for n=0..29.


FORMULA

a(n) = floor(sqrt(derangements(n))).


MATHEMATICA

FSFromExpSeries[f_, x_, n_] := Map[Floor[Sqrt[#]]&, CoefficientList[Series[f, {x, 0, n}], x]Table[k!, {k, 0, n}]]
FSFromExpSeries[Exp[x]/(1x), x, 100]


CROSSREFS

Sequence in context: A202839 A007561 A274295 * A202846 A107269 A086811
Adjacent sequences: A192673 A192674 A192675 * A192677 A192678 A192679


KEYWORD

nonn


AUTHOR

Emanuele Munarini, Jul 07 2011


STATUS

approved



