A174619 a(n) = A174618(n) + A174618(n+1).

1, 1, 1, 2, 2, 3, 3, 4, 5, 6, 8, 10, 13, 17, 21, 28, 34, 45, 55, 72, 89, 116, 144, 188, 233, 305, 377, 494, 610, 799, 987, 1292, 1597, 2090, 2584, 3382, 4181, 5473, 6765, 8856, 10946, 14329, 17711, 23184, 28657, 37512, 46368, 60696, 75025, 98209, 121393, 158906, 196418, 257115, 317811

Offset

1,4

Links

Table of n, a(n) for n=1..55.

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

Formula

a(2n) = A024490(n+1). a(2n+1)= A000045(n+1).

a(n) = 2*a(n-2) -a(n-4) +a(n-8). G.f.: -x*(1+x)*(x^3-x^2+1) / ( (x^4-x^2+1)*(x^4+x^2-1) ). - R. J. Mathar, Jan 27 2011

Mathematica

LinearRecurrence[{0, 2, 0, -1, 0, 0, 0, 1}, {1, 1, 1, 2, 2, 3, 3, 4}, 60] (* Harvey P. Dale, Sep 09 2022 *)

Crossrefs

Cf. A024490, A000045.

Sequence in context: A120160 A017980 A064650 * A130083 A369787 A363994

Adjacent sequences: A174616 A174617 A174618 * A174620 A174621 A174622

Keyword

nonn,easy

Author

Mark Dols, Mar 23 2010

Status

approved