A037687 Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,0,3,2.

1, 10, 103, 1032, 10321, 103210, 1032103, 10321032, 103210321, 1032103210, 10321032103, 103210321032, 1032103210321, 10321032103210, 103210321032103, 1032103210321032

Offset

1,2

Links

Table of n, a(n) for n=1..16.

Index entries for linear recurrences with constant coefficients, signature (10,0,0,1,-10).

Formula

a(n) = 10*a(n-1) + (1/2)*((n mod 4) - ((n+1) mod 4) + ((n+2) mod 4) + ((n+3) mod 4)), with a(0)=0. - Paolo P. Lava, Jul 30 2009

G.f.: x*(1+3*x^2+2*x^3) / ( (x-1)*(10*x-1)*(1+x)*(x^2+1) ). - R. J. Mathar, Aug 12 2013

Prog

(PARI) Vec(x*(1+3*x^2+2*x^3)/((x-1)*(10*x-1)*(1+x)*(x^2+1)) + O(x^25)) \\ Jinyuan Wang, Apr 14 2020

Crossrefs

Sequence in context: A158240 A087393 A037596 * A015588 A162667 A227014

Adjacent sequences: A037684 A037685 A037686 * A037688 A037689 A037690

Keyword

nonn,base,easy

Author

Clark Kimberling

Status

approved