A037520 Base 3 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,0.

2, 7, 21, 65, 196, 588, 1766, 5299, 15897, 47693, 143080, 429240, 1287722, 3863167, 11589501, 34768505, 104305516, 312916548, 938749646, 2816248939, 8448746817, 25346240453, 76038721360, 228116164080, 684348492242

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• easy

Links

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

Programs

Mathematica

With[{c=PadRight[{},27,{2,1,0}]},Table[FromDigits[Take[c,n],3], {n,25}]] (* Harvey P. Dale, Nov 08 2011 *)

Formula

G.f.: x*(2+x) / ( (x-1)*(3*x-1)*(1+x+x^2) ). - R. J. Mathar, Nov 21 2011