A026397 Sum{T(n-k,k)}, 0<=k<=[ n/2 ], where T is the array in A026386.

1, 2, 3, 6, 10, 17, 31, 53, 92, 163, 282, 492, 863, 1501, 2621, 4582, 7987, 13946, 24354, 42489, 74179, 129497, 226000, 394523, 688670, 1202020, 2098239, 3662553, 6392969, 11159290, 19478867, 34000750, 59349706, 103596641

Offset

0,2

Links

Table of n, a(n) for n=0..33.

Index entries for linear recurrences with constant coefficients, signature (0,1,3,1).

Formula

Pairwise sums of A026385. - _Ralf Stephan_, Jul 22 2003

G.f.: [(1+x)(1+x+x^2)]/[1-x^2-3x^3-x^4]. - _Ralf Stephan_, Apr 30 2004

Mathematica

LinearRecurrence[{0, 1, 3, 1}, {1, 2, 3, 6}, 40] (* _Harvey P. Dale_, Apr 15 2015 *)

Crossrefs

Sequence in context: A135431 A123908 A233268 * A193200 A026779 A081028

Adjacent sequences: A026394 A026395 A026396 * A026398 A026399 A026400

Keyword

nonn

Author

_Clark Kimberling_

Status

approved