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A157057 Number of integer sequences of length n+1 with sum zero and sum of absolute values 16 1
2, 48, 642, 6040, 44130, 264936, 1356194, 6077196, 24314490, 88206140, 293744154, 907129236, 2619716554, 7125357540, 18363363690, 45076309166, 105864434424, 238815143406, 519252051080, 1091481669390, 2224042468032, 4403475647758, 8489857618992, 15969368635950 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

a(n)=T(n,8); 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^14 +7*x^13 +49*x^12 +147*x^11 +441*x^10 +735*x^9 +1225*x^8 +1225*x^7 +1225*x^6 +735*x^5 +441*x^4 +147*x^3 +49*x^2 +7*x +1) / (x -1)^17. [Colin Barker, Jan 25 2013]

CROSSREFS

Cf. A103881, A156554.

Sequence in context: A231654 A005429 A035606 * A290690 A013523 A260846

Adjacent sequences:  A157054 A157055 A157056 * A157058 A157059 A157060

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin Feb 22 2009

STATUS

approved

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Last modified May 29 04:33 EDT 2020. Contains 334697 sequences. (Running on oeis4.)