A037540 - OEIS

A037540

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

1, 9, 64, 449, 3145, 22016, 154113, 1078793, 7551552, 52860865, 370026057, 2590182400, 18131276801, 126918937609, 888432563264, 6219027942849, 43533195599945, 304732369199616, 2133126584397313

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OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

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

FORMULA

G.f.: x*(1+x)^2 / ( (x-1)*(7*x-1)*(1+x+x^2) ). - R. J. Mathar, Apr 30 2015

MATHEMATICA

Table[FromDigits[PadRight[{}, n, {1, 2, 1}], 7], {n, 20}] (* or *) LinearRecurrence[{7, 0, 1, -7}, {1, 9, 64, 449}, 20] (* Harvey P. Dale, Mar 17 2026 *)

CROSSREFS

Sequence in context: A357649 A231822 A049684 * A037484 A383070 A378566

Adjacent sequences: A037537 A037538 A037539 * A037541 A037542 A037543

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling

STATUS

approved