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A175287 Partial sums of ceiling(n^2/4). 3
0, 1, 2, 5, 9, 16, 25, 38, 54, 75, 100, 131, 167, 210, 259, 316, 380, 453, 534, 625, 725, 836, 957, 1090, 1234, 1391, 1560, 1743, 1939, 2150, 2375, 2616, 2872, 3145, 3434, 3741, 4065, 4408, 4769, 5150, 5550, 5971, 6412, 6875, 7359, 7866, 8395, 8948, 9524, 10125, 10750 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Partial sums of A004652.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

L. Colmenarejo, Combinatorics on several families of Kronecker coefficients related to plane partitions, arXiv:1604.00803 [math.CO], 2016. See Table 1 p. 5.

Mircea Merca, Inequalities and Identities Involving Sums of Integer Functions J. Integer Sequences, Vol. 14 (2011), Article 11.9.1.

Index entries for linear recurrences with constant coefficients, signature (3,-2,-2,3,-1).

FORMULA

a(n) = round((2*n+1)*(2*n^2+2*n+9)/48).

a(n) = floor((n+1)*(2*n^2+n+9)/24).

a(n) = ceiling((2*n^3+3*n^2+10*n)/24).

a(n) = round((2*n^3+3*n^2+10*n)/24).

a(n) = a(n-4)+n^2-3*n+5 , n>3.

G.f.: x*(1-x+x^2) / ( (1+x)*(x-1)^4 ).

a(n) = (2*n*(2*n^2+3*n+10)-9*(-1)^n+9)/48. - Bruno Berselli, Dec 03 2010

EXAMPLE

a(4) = ceil(0/4)+ceil(1/4)+ceil(4/4)+ceil(9/4)+ceil(16/4) = 0+1+1+3+4=9.

MAPLE

a:= n-> round((2*n^(3)+3*n^(2)+10*n)/24): seq(a(n), n=0..20);

MATHEMATICA

Table[Sum[Ceiling[i^2/4], {i, 0, n}], {n, 0, 49}] (* or *) Table[(2n(2n^2 + 3n + 10) -9(-1)^n + 9)/48, {n, 0, 49}] (* Alonso del Arte, Dec 03 2010 *)

CoefficientList[Series[(x^3 - x^2 + x)/(x^5 - 3 x^4 + 2 x^3 + 2 x^2 - 3 x + 1), {x, 0, 50}], x] (* Vincenzo Librandi, Mar 26 2014 *)

Accumulate[Ceiling[Range[0, 50]^2/4]] (* or *) LinearRecurrence[{3, -2, -2, 3, -1}, {0, 1, 2, 5, 9}, 60] (* Harvey P. Dale, Nov 19 2014 *)

PROG

(MAGMA) [Floor((n+1)*(2*n^2+n+9)/24): n in [0..60]]; // Vincenzo Librandi, Jun 22 2011

(PARI) x='x+O('x^99); concat(0, Vec((x^3-x^2+x)/ (x^5-3*x^4+2*x^3+2*x^2-3*x+1))) \\ Altug Alkan, Apr 05 2016

CROSSREFS

Cf. A004652.

Sequence in context: A169740 A282044 A138226 * A284917 A007979 A097701

Adjacent sequences:  A175284 A175285 A175286 * A175288 A175289 A175290

KEYWORD

nonn,easy

AUTHOR

Mircea Merca, Dec 03 2010

STATUS

approved

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Last modified November 19 03:53 EST 2017. Contains 294912 sequences.