A037705 Base-7 digits are, in order, the first n terms of the periodic sequence with initial period 1,3,0,2.

1, 10, 70, 492, 3445, 24118, 168826, 1181784, 8272489, 57907426, 405351982, 2837463876, 19862247133, 139035729934, 973250109538, 6812750766768, 47689255367377, 333824787571642, 2336773513001494, 16357414591010460, 114501902137073221, 801513314959512550

Offset

1,2

Links

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

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

Formula

a(n) = 7*a(n-1) + a(n-4) - 7*a(n-5).

From Colin Barker, Dec 24 2015: (Start)

a(n) = 1/200*(25*(-1)^n-(8+6*i)*(-i)^n-(8-6*i)*i^n+41*7^n-50) where i=sqrt(-1).

G.f.: x*(1+3*x+2*x^3) / ((1-x)*(1+x)*(1-7*x)*(1+x^2)).

(End)

Prog

(PARI) Vec(x*(1+3*x+2*x^3)/((1-x)*(1+x)*(1-7*x)*(1+x^2)) + O(x^30)) \\ Colin Barker, Dec 24 2015

Crossrefs

Sequence in context: A337992 A257114 A037600 * A126505 A038779 A246427

Adjacent sequences: A037702 A037703 A037704 * A037706 A037707 A037708

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved