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A204558 Row sums of the triangle A045975. 4
1, 6, 45, 120, 325, 630, 1225, 2016, 3321, 4950, 7381, 10296, 14365, 19110, 25425, 32640, 41905, 52326, 65341, 79800, 97461, 116886, 140185, 165600, 195625, 228150, 266085, 306936, 354061, 404550, 462241, 523776, 593505, 667590, 750925, 839160, 937765 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) = sum(A045975(n,k): k = 1 .. n);

a(n) = n * (if n even then A035328(n/2) else A005817((n+1)/2)). [Reinhard Zumkeller, Jan 18 2012]

LINKS

Table of n, a(n) for n=1..37.

FORMULA

Conjecture: a(n) = (n^2*(-(-1)^n+n^2))/2. G.f.: -x*(x^6 +4*x^5 +31*x^4 +24*x^3 +31*x^2 +4*x +1) / ((x -1)^5*(x +1)^3). - Colin Barker, Apr 02 2013

PROG

(Haskell)

a204558 = sum . a045975_row

CROSSREFS

Sequence in context: A006086 A273507 A131513 * A123141 A122096 A302709

Adjacent sequences:  A204555 A204556 A204557 * A204559 A204560 A204561

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jan 18 2012

STATUS

approved

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Last modified October 17 19:36 EDT 2018. Contains 316293 sequences. (Running on oeis4.)