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A137247 a(n) = 4a(n-1) - 6a(n-2) + 6a(n-3) - 3a(n-4), with initial terms 0, 0, 0, 1. 0
0, 0, 0, 1, 4, 10, 22, 49, 112, 256, 580, 1309, 2956, 6682, 15106, 34141, 77152, 174352, 394024, 890473, 2012404, 4547866, 10277806, 23227033, 52491280, 118626160, 268085740, 605852581, 1369179004, 3094236490, 6992730202, 15803018149 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Essentially the partial sums of A052103. - R. J. Mathar, Apr 01 2008

LINKS

Table of n, a(n) for n=0..31.

Index entries for linear recurrences with constant coefficients, signature (4, -6, 6, -3).

FORMULA

From R. J. Mathar, Apr 01 2008: (Start)

O.g.f.: x^3/((x-1)*(3*x^3-3*x^2+3*x-1)).

A052103(n) = a(n+2) - a(n+1). (End)

a(n) = -1/2 + (1/6)*(1+((1/2)*i)*108^(1/6) - (1/2)*2^(1/3))^n + (1/6)*(1-(1/2)*i)*108^(1/6) - (1/2)*2^(1/3))^n + (1/6)*(1+2^(1/3))^n, with n >= 0 and i=sqrt(-1). - Paolo P. Lava, Jun 09 2008

MAPLE

a[0]:=0: a[1]:=0: a[2]:=0: a[3]:=1: for n from 4 to 30 do a[n]:=4*a[n-1]-6*a[n-2]+6*a[n-3]-3*a[n-4] end do: seq(a[n], n=0..30); # Emeric Deutsch, Mar 17 2008

CROSSREFS

Cf. A052103.

Sequence in context: A056112 A118430 A178452 * A155407 A318416 A124697

Adjacent sequences:  A137244 A137245 A137246 * A137248 A137249 A137250

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Mar 10 2008

EXTENSIONS

More terms from R. J. Mathar, Rolf Pleisch and Emeric Deutsch, Apr 01 2008

Name edited by Michel Marcus, Jan 29 2019

STATUS

approved

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Last modified February 23 18:37 EST 2019. Contains 320438 sequences. (Running on oeis4.)