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 A157058 Number of integer sequences of length n+1 with sum zero and sum of absolute values 18. 1

%I

%S 2,54,812,8580,70310,472626,2703512,13507416,60110030,241925530,

%T 891454124,3037849828,9654482474,28818500830,81289041680,217815522736,

%U 556959705302,1364497268946,3214138597460,7302195414780,16045139112002,34183012888134,70764981877592

%N Number of integer sequences of length n+1 with sum zero and sum of absolute values 18.

%H T. D. Noe, <a href="/A157058/b157058.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n)=T(n,9); T(n,k)=sum({i=1..n}binomial(n+1,i)*binomial(k-1,i-1)*binomial(n-i+k,k))

%F G.f.: -2*x*(x^16 +8*x^15 +64*x^14 +224*x^13 +784*x^12 +1568*x^11 +3136*x^10 +3920*x^9 +4900*x^8 +3920*x^7 +3136*x^6 +1568*x^5 +784*x^4 +224*x^3 +64*x^2 +8*x +1) / (x -1)^19. [_Colin Barker_, Jan 25 2013]

%Y Cf. A103881, A156554.

%K nonn,easy

%O 1,1

%A _R. H. Hardin_ Feb 22 2009

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Last modified June 7 02:48 EDT 2020. Contains 334836 sequences. (Running on oeis4.)