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

Offset

1,2

Links

Table of n, a(n) for n=1..19.

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

Crossrefs

Sequence in context: A357649 A231822 A049684 * A037484 A013566 A056769

Adjacent sequences: A037537 A037538 A037539 * A037541 A037542 A037543

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved