A021449 Decimal expansion of 1/445.

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

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• cons
• easy

Comments

Expansion in any base b >= 3 of 2/(b(b-1)(b+1)) = 2/(b^3-b). E.g., 1/12 in base 3, 1/30 in base 4, 1/60 in base 5, etc. - Franklin T. Adams-Watters, Nov 07 2006

Links

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

Crossrefs

Cf. A027480, A021093.

Programs

Mathematica

Join[{0,0},RealDigits[1/445,10,120][[1]]] (* Harvey P. Dale, Aug 25 2015 *)

PARI

1/445. \\ Charles R Greathouse IV, Dec 05 2011

Formula

From Chai Wah Wu, May 08 2025: (Start)

a(n) = a(n-1) - a(n-22) + a(n-23) for n > 23.

G.f.: x^2*(-2*x^21 - 6*x^20 + 5*x^19 - x^18 - 5*x^17 + 5*x^16 + 4*x^14 - 4*x^13 - 2*x^12 - x^11 - x^10 - x^8 + x^7 + 8*x^6 - 8*x^5 + 6*x^4 - 3*x^3 - 2*x^2 - 2)/(x^23 - x^22 + x - 1). (End)