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A058373 (1/6)*(2*n - 3)*(n + 2)*(n + 1). 7
0, 0, -1, -1, 2, 10, 25, 49, 84, 132, 195, 275, 374, 494, 637, 805, 1000, 1224, 1479, 1767, 2090, 2450, 2849, 3289, 3772, 4300, 4875, 5499, 6174, 6902, 7685, 8525, 9424, 10384, 11407, 12495, 13650, 14874, 16169, 17537, 18980, 20500, 22099 (list; graph; refs; listen; history; text; internal format)
OFFSET

-2,5

COMMENTS

For n>=0, real parts of sum_(k=0)^n (k+i)^2, where i=sqrt(-1). [Bruno Berselli, Jan 24 2014]

LINKS

Table of n, a(n) for n=-2..40.

FORMULA

a(n) = 2*C(n,3)-C(n,2), n>=0. - Zerinvary Lajos, Nov 25 2006

MAPLE

[seq(2*binomial(n, 3)-binomial(n, 2), n=0..42)]; - Zerinvary Lajos, Nov 25 2006

a:=n->sum((j-2)*j, j=0..n): seq(a(n), n=-1..41); - Zerinvary Lajos, Dec 02 2006

seq(add (k^2-n, k =0..n), n=-1..41 ); - Zerinvary Lajos, Aug 26 2007

MATHEMATICA

s=0; lst={0, s}; Do[s+=n^2-1; AppendTo[lst, s], {n, 0, 6!, 1}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 07 2008 *)

Table[Sum[i^2 - 2*i, {i, 0, n}], {n, -1, 41}] (* Zerinvary Lajos, Jul 10 2009 *)

CROSSREFS

Cf. A236377: real part of sum_(k=0)^n (k + i^k)^2, i=sqrt(-1). [Bruno Berselli, Jan 25 2014]

Sequence in context: A119062 A270822 A248117 * A167386 A027719 A254709

Adjacent sequences:  A058370 A058371 A058372 * A058374 A058375 A058376

KEYWORD

sign,easy

AUTHOR

N. J. A. Sloane, Dec 18 2000

STATUS

approved

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Last modified March 24 01:22 EDT 2017. Contains 283984 sequences.