A109165 a(n) = 5*a(n-2) - 2*a(n-4), n >= 4.

1, 2, 5, 10, 23, 46, 105, 210, 479, 958, 2185, 4370, 9967, 19934, 45465, 90930, 207391, 414782, 946025, 1892050, 4315343, 8630686, 19684665, 39369330, 89792639, 179585278, 409593865, 819187730, 1868384047, 3736768094, 8522732505

Offset

0,2

Comments

Floretion Algebra Multiplication Program, FAMP Code: 4kbaseksigcycsumseq[ - .25'i - .25i' + .25'ii' + .25'jj' + .25'kk' + .25'jk' + .25'kj' + .25e], sumtype: (Y[15], *, vesy)

Links

Table of n, a(n) for n=0..30.

Index entries for linear recurrences with constant coefficients, signature (0,5,0,-2).

Formula

a(2n) = A107839(n), a(2n+1) = A106709(n+1), a(n) - a(n-1) = A005824(n+2).

G.f.: (2*x+1)/(1-5*x^2+2*x^4).

Crossrefs

Cf. A107839, A106709, A005824, A054486.

Sequence in context: A191386 A323988 A026677 * A018344 A284181 A365376

Adjacent sequences: A109162 A109163 A109164 * A109166 A109167 A109168

Keyword

easy,nonn

Author

Creighton Dement, Aug 18 2005

Status

approved