A204558 - OEIS

A204558

Row sums of the triangle A045975.

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

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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)