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 A192551 a(n) = sum(abs(stirling1(n+1,k+1))*k!^2,k=0..n) 1

%I #9 Jan 03 2013 03:36:48

%S 1,2,9,77,1150,27394,957040,45996880,2904500048,232935169536,

%T 23114775120624,2779720331819760,398266855573740192,

%U 67024510463455711776,13090037070947651891136,2936252114196522165716544,749684382637966175707918848

%N a(n) = sum(abs(stirling1(n+1,k+1))*k!^2,k=0..n)

%H Vincenzo Librandi, <a href="/A192551/b192551.txt">Table of n, a(n) for n = 0..200</a>

%F a(n) ~ sqrt(e)*(n!)^2. - _Vaclav Kotesovec_, Jan 02 2013

%t Table[Sum[Abs[StirlingS1[n+1,k+1]]k!^2,{k,0,n}],{n,0,100}]

%o (Maxima) makelist(sum(abs(stirling1(n+1,k+1))*k!^2,k,0,n),n,0,24);

%K nonn

%O 0,2

%A _Emanuele Munarini_, Jul 04 2011

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Last modified April 22 22:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)