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A157056 Number of integer sequences of length n+1 with sum zero and sum of absolute values 14. 1
2, 42, 492, 4060, 26070, 137886, 623576, 2476296, 8809110, 28512110, 85014204, 235895244, 614266354, 1511679210, 3536846160, 7907476016, 16967926746, 35078339106, 70098276620, 135798494460, 255689552382, 468969729382, 839584669992, 1469778991800, 2520031983950 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (15,-105,455,-1365,3003,-5005,6435,-6435,5005,-3003,1365,-455,105,-15,1).

FORMULA

a(n)=T(n,7); T(n,k)=sum({i=1..n}binomial(n+1,i)*binomial(k-1,i-1)*binomial(n-i+k,k))

G.f.: -2*x*(x^12 +6*x^11 +36*x^10 +90*x^9 +225*x^8 +300*x^7 +400*x^6 +300*x^5 +225*x^4 +90*x^3 +36*x^2 +6*x +1) / (x -1)^15. [Colin Barker, Jan 25 2013]

CROSSREFS

Cf. A103881, A156554.

Sequence in context: A202865 A070808 A229474 * A180425 A140170 A318247

Adjacent sequences:  A157053 A157054 A157055 * A157057 A157058 A157059

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin Feb 22 2009

STATUS

approved

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Last modified May 31 06:52 EDT 2020. Contains 334747 sequences. (Running on oeis4.)