A037681 Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,3,2.

1, 4, 19, 78, 313, 1252, 5011, 20046, 80185, 320740, 1282963, 5131854, 20527417, 82109668, 328438675, 1313754702, 5255018809, 21020075236, 84080300947, 336321203790, 1345284815161, 5381139260644, 21524557042579, 86098228170318

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Index entries for linear recurrences with constant coefficients, signature (4,0,0,1,-4).

Formula

G.f.: x*(1+3*x^2+2*x^3) / ( (x-1)*(4*x-1)*(1+x)*(x^2+1) ). - R. J. Mathar, May 04 2015

Mathematica

Table[FromDigits[PadRight[{}, n, {1, 0, 3, 2}], 4], {n, 30}] (* or *) LinearRecurrence[{4, 0, 0, 1, -4}, {1, 4, 19, 78, 313}, 30] (* Harvey P. Dale, May 10 2023 *)

Crossrefs

Sequence in context: A037590 A359087 A378499 * A156760 A320088 A122909

Adjacent sequences: A037678 A037679 A037680 * A037682 A037683 A037684

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved