A021249 - OEIS

%I #13 Jul 13 2016 11:09:08

%S 0,0,4,0,8,1,6,3,2,6,5,3,0,6,1,2,2,4,4,8,9,7,9,5,9,1,8,3,6,7,3,4,6,9,

%T 3,8,7,7,5,5,1,0,2,0,4,0,8,1,6,3,2,6,5,3,0,6,1,2,2,4,4,8,9,7,9,5,9,1,

%U 8,3,6,7,3,4,6,9,3,8,7,7,5,5,1,0,2,0,4,0,8,1,6,3,2,6,5,3,0,6,1

%N Decimal expansion of 1/245.

%F Equals 10*A021053-1/5 . [From _R. J. Mathar_, Oct 25 2008]

%F From _Chai Wah Wu_, Jul 13 2016: (Start)

%F a(n) = a(n-1) - a(n-21) + a(n-22) for n > 22.

%F G.f.: x^2*(-2*x^20 + 2*x^19 - x^18 - 4*x^17 - 2*x^15 - x^13 + 5*x^12 - 6*x^11 + 3*x^10 + 2*x^9 + x^8 - 4*x^7 + x^6 + 3*x^5 - 5*x^4 + 7*x^3 - 8*x^2 + 4*x - 4)/(x^22 - x^21 + x - 1). (End)

%t PadLeft[First@ #, Length@ First@ # + Abs@ Last@ #] &@ RealDigits[N[1/245, 120]] (* _Michael De Vlieger_, Jul 13 2016 *)

%o (PARI) 1/245. \\ _Altug Alkan_, Jul 13 2016

%K nonn,cons

%O 0,3

%A _N. J. A. Sloane_.