login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A037691 Base-7 digits are, in order, the first n terms of the periodic sequence with initial period 1,2,0,3. 2
1, 9, 63, 444, 3109, 21765, 152355, 1066488, 7465417, 52257921, 365805447, 2560638132, 17924466925, 125471268477, 878298879339, 6148092155376, 43036645087633, 301256515613433, 2108795609294031, 14761569265058220, 103330984855407541, 723316893987852789 (list; graph; refs; listen; history; text; internal format)
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-(6-8*i)*(-i)^n-(6+8*i)*i^n+37*7^n-50) where i=sqrt(-1).

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

(End)

MATHEMATICA

Table[FromDigits[PadRight[{}, n, {1, 2, 0, 3}], 7], {n, 30}] (* Harvey P. Dale, May 24 2017 *)

PROG

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

CROSSREFS

Sequence in context: A201885 A225964 A037508 * A206816 A336670 A065025

Adjacent sequences:  A037688 A037689 A037690 * A037692 A037693 A037694

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 23 14:09 EDT 2021. Contains 347617 sequences. (Running on oeis4.)