A319842 a(n) = 8 * A104720(n) + ceiling(n/2).

8, 89, 897, 8978, 89786, 897867, 8978675, 89786756, 897867564, 8978675645, 89786756453, 897867564534, 8978675645342, 89786756453423, 897867564534231, 8978675645342312, 89786756453423120, 897867564534231201, 8978675645342312009, 89786756453423120090, 897867564534231200898, 8978675645342312008979

Offset

0,1

Links

Colin Barker, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (11,-9,-11,10).

Formula

a(n) = (198*n - 243*(-1)^n + 2^(n+8)*5^(n+3) - 3245)/3564.

From Colin Barker, Sep 29 2018: (Start)

G.f.: (8 + x - 10*x^2) / ((1 - x)^2*(1 + x)*(1 - 10*x)).

a(n) = 11*a(n-1) - 9*a(n-2) - 11*a(n-3) + 10*a(n-4) for n>3.

(End)

Mathematica

a[n_]:=(198*n - 243*(-1)^n + 2^(n+8)*5^(n+3) - 3245)/3564; Array[a, 50, 0] (* Stefano Spezia, Sep 29 2018 *)
LinearRecurrence[{11, -9, -11, 10}, {8, 89, 897, 8978}, 40] (* Harvey P. Dale, Apr 11 2019 *)

Prog

(PARI) {a(n) = (198*n-243*(-1)^n+2^(n+8)*5^(n+3)-3245)/3564}
(PARI) Vec((8 + x - 10*x^2) / ((1 - x)^2*(1 + x)*(1 - 10*x)) + O(x^25)) \\ Colin Barker, Sep 29 2018

Crossrefs

Cf. A104720, A110654.

Sequence in context: A068498 A061000 A240457 * A072352 A099100 A208265

Adjacent sequences: A319839 A319840 A319841 * A319843 A319844 A319845

Keyword

nonn,easy

Author

Seiichi Manyama, Sep 29 2018

Status

approved