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

Offset: 1

Author

Reinhard Zumkeller, Jan 18 2012

Keywords

• nonn

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]

Programs

Haskell

a204558 = sum . a045975_row

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