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A157055 Number of integer sequences of length n+1 with sum zero and sum of absolute values 12 1
2, 36, 362, 2570, 14240, 65226, 256508, 889716, 2777370, 7925720, 20934474, 51697802, 120353324, 265953170, 561075720, 1135620536, 2214405618, 4175000796, 7634582090, 13577591370, 23539760552, 39868752506, 66087441092, 107392877100, 171332460650, 268708978512 (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 (13,-78,286,-715,1287,-1716,1716,-1287,715,-286,78,-13,1).

FORMULA

a(n)=T(n,6); 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^10 +5*x^9 +25*x^8 +50*x^7 +100*x^6 +100*x^5 +100*x^4 +50*x^3 +25*x^2 +5*x +1) / (x -1)^13. [Colin Barker, Jan 25 2013]

CROSSREFS

Cf. A103881, A156554.

Sequence in context: A126735 A229679 A119582 * A057407 A286266 A193127

Adjacent sequences:  A157052 A157053 A157054 * A157056 A157057 A157058

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin Feb 22 2009

STATUS

approved

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Last modified May 25 06:50 EDT 2020. Contains 334584 sequences. (Running on oeis4.)