A125849 a(n) = Sum_{m=1..n-1} floor(m(n-2)/2)^2.

0, 0, 0, 1, 14, 62, 220, 547, 1260, 2444, 4560, 7685, 12650, 19466, 29484, 42567, 60760, 83672, 114240, 151689, 200070, 258070, 331100, 417131, 523204, 646372, 795600, 966797, 1171170, 1403234, 1676780, 1984655, 2343600, 2744496, 3207424

Offset

0,5

Links

Table of n, a(n) for n=0..34.

Formula

G.f.: (x^3*(x^6+18*x^5+35*x^4+62*x^3+31*x^2+12*x+1))/((x+1)^4*(x-1)^6). - Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009

Maple

for n from 0 to 15 do add( floor(m*(n-2)/2)^2, m=1..n-1) ; print(n, %) ; od: # R. J. Mathar

Mathematica

f[n_] := Sum[ Floor[m (n - 2)/2]^2, {m, n - 1}]; Table[ f@n, {n, 0, 35}] (* Robert G. Wilson v, Aug 03 2008 *)

Crossrefs

Sequence in context: A252255 A025415 A307253 * A003695 A022674 A044152

Adjacent sequences: A125846 A125847 A125848 * A125850 A125851 A125852

Keyword

nonn

Author

Jerry Metzger, Jul 09 2008

Extensions

More terms from Robert G. Wilson v, Aug 03 2008

Status

approved