A152896 a=b=c=0;c(n)=c+n+a;b(n)=b+n+c;a(n)=a+n+b.

0, 3, 15, 55, 183, 588, 1865, 5887, 18550, 58414, 183904, 578936, 1822459, 5736946, 18059358, 56849069, 178955165, 563332829, 1773314909, 5582216334, 17572253459, 55315679765, 174128175040, 548137914348, 1725482812062

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Index entries for linear recurrences with constant coefficients, signature (6, -12, 11, -5, 1).

Formula

G.f.: x^2(3-3x+x^2)/((1-x)^2*(1-4x+3x^2-x^3)). a(n)=6*a(n-1)-12*a(n-2)+11*a(n-3)-5*a(n-4)+a(n-5). [From R. J. Mathar, Dec 15 2008]

Mathematica

lst={}; a=b=c=0; Do[c+=n+a; b+=n+c; a+=n+b; AppendTo[lst, a], {n, 0, 2*4!}]; lst
LinearRecurrence[{6, -12, 11, -5, 1}, {0, 3, 15, 55, 183}, 30] (* Harvey P. Dale, Dec 11 2014 *)

Crossrefs

Cf. A152891, A152895

Sequence in context: A176288 A119113 A286185 * A007973 A261737 A015249

Adjacent sequences: A152893 A152894 A152895 * A152897 A152898 A152899

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Dec 14 2008

Status

approved