A033134 Base-7 digits are, in order, the first n terms of the periodic sequence with initial period 1,1,0.

1, 8, 56, 393, 2752, 19264, 134849, 943944, 6607608, 46253257, 323772800, 2266409600, 15864867201, 111054070408, 777378492856, 5441649449993, 38091546149952, 266640823049664, 1866485761347649, 13065400329433544, 91457802306034808, 640204616142243657

Offset

1,2

Links

Colin Barker, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (7,0,1,-7).

Formula

a(n) = 7*a(n-1) + a(n-3) - 7*a(n-4).

a(n) = floor( (28/171)*7^n ). - Tani Akinari, Jul 16 2014

G.f.: x*(1+x) / ((1-x)*(1-7*x)*(1+x+x^2)). - Colin Barker, Dec 24 2015

Example

The first six terms have base-7 representations 1, 11, 110, 1101, 11011, 110110.

Prog

(PARI) Vec(x*(1+x)/((1-x)*(1-7*x)*(1+x+x^2)) + O(x^30)) \\ Colin Barker, Dec 24 2015

Crossrefs

Cf. A033137 (similar in base 10).

Sequence in context: A170689 A003950 A252701 * A126985 A323699 A323700

Adjacent sequences: A033131 A033132 A033133 * A033135 A033136 A033137

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved