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Search: id:A055214
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A055214 a(n) = 2n*a(n-1) - 1. +0
1
1, 1, 3, 17, 135, 1349, 16187, 226617, 3625871, 65265677, 1305313539, 28716897857, 689205548567, 17919344262741, 501741639356747, 15052249180702409, 481671973782477087, 16376847108604220957 (list; graph; listen)
OFFSET

0,3

FORMULA

a(n) = ceiling[2^n * n! * (2-sqrt(e))] = ceiling[A000165(n) * (2-sqrt(e))]

EXAMPLE

a(3) = 2*3*a(2)-1 = 6*3-1 = 17

MATHEMATICA

s=-1; lst={Abs[s]}; Do[s+=s++n; AppendTo[lst, Abs[s]], {n, 1, 5!, 2}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 23 2008]

CROSSREFS

Sequence in context: A074524 A163684 A093986 this_sequence A105630 A006290 A060003

Adjacent sequences: A055211 A055212 A055213 this_sequence A055215 A055216 A055217

KEYWORD

easy,nonn

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Jun 19 2000

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jul 04 2000

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Last modified December 17 19:39 EST 2009. Contains 170821 sequences.


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