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A037736
Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,1,0,3.
0
2, 21, 210, 2103, 21032, 210321, 2103210, 21032103, 210321032, 2103210321, 21032103210, 210321032103, 2103210321032, 21032103210321, 210321032103210, 2103210321032103
OFFSET
1,1
FORMULA
a(n) = 10*a(n-1) + a(n-4) - 10*a(n-5). G.f: x*(2+x+3*x^3) / ((x-1)*(10*x-1)*(1+x)*(1+x^2)). - R. J. Mathar, Oct 05 2009
PROG
(PARI) Vec(x*(2+x+3*x^3)/((x-1)*(10*x-1)*(1+x)*(1+x^2)) + O(x^25)) \\ Jinyuan Wang, Apr 14 2020
CROSSREFS
Sequence in context: A303500 A037527 A131584 * A328073 A329318 A037559
KEYWORD
nonn,base,easy
STATUS
approved