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

1,5

Comments

Also the NW-SE diagonal sums of A173402.

Links

Table of n, a(n) for n=1..36.

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

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

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 *)

Crossrefs

Cf. A112468, A000045, A173398, A173402

Sequence in context: A080105 A023557 A293671 * A255126 A052185 A136241

Adjacent sequences: A173431 A173432 A173433 * A173435 A173436 A173437

Keyword

nonn,easy

Author

Mark Dols, Feb 18 2010

Status

approved