A173434 a(n) = (A000045(n)-A173432(n))/2.

0, 0, 0, 1, 2, 4, 6, 10, 16, 27, 44, 72, 116, 188, 304, 493, 798, 1292, 2090, 3382, 5472, 8855, 14328, 23184, 37512, 60696, 98208, 158905, 257114, 416020, 673134, 1089154, 1762288, 2851443, 4613732, 7465176

Offset: 1

Author

Mark Dols, Feb 18 2010

Keywords

• nonn
• easy

Comments

Also the NW-SE diagonal sums of A173402.

Links

• Index entries for linear recurrences with constant coefficients, signature (2,0,-2,2,0,-1).

Crossrefs

Cf. A112468, A000045, A173398, A173402

Programs

Mathematica

CoefficientList[Series[x^4/((x-1)(1+x)(x^2-x+1)(x^2+x-1)),{x,0,40}],x] (* or *) LinearRecurrence[{2,0,-2,2,0,-1},{0,0,0,0,1,2},40] (* Harvey P. Dale, Jun 29 2021 *)

Formula

a(n) + A173433(n) = A000045(n).

a(n)= 2*a(n-1) -2*a(n-3) +2*a(n-4) -a(n-6). - R. J. Mathar, Mar 01 2010

G.f.: x^4 / ( (x-1)*(1+x)*(x^2-x+1)*(x^2+x-1) ). - R. J. Mathar, Nov 03 2016