A037568 Base 3 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,2.

2, 7, 23, 71, 214, 644, 1934, 5803, 17411, 52235, 156706, 470120, 1410362, 4231087, 12693263, 38079791, 114239374, 342718124, 1028154374, 3084463123, 9253389371, 27760168115, 83280504346, 249841513040, 749524539122

Offset

1,1

Links

Table of n, a(n) for n=1..25.

Index entries for linear recurrences with constant coefficients, signature (3,0,1,-3).

Formula

G.f.: x*(2+x+2*x^2) / ( (x-1)*(3*x-1)*(1+x+x^2) ). - R. J. Mathar, Apr 30 2015

Mathematica

Table[FromDigits[PadRight[{}, n, {2, 1, 2}], 3], {n, 30}] (* Harvey P. Dale, Apr 07 2022 *)

Crossrefs

Sequence in context: A210581 A037488 A129669 * A076656 A085387 A147970

Adjacent sequences: A037565 A037566 A037567 * A037569 A037570 A037571

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved