A067089 Floor(X/Y) where X = concatenation of (2n), (2n-1), ... down to n+1 and Y = concatenation of n, n-1, n-2, ... down to 1.

2, 2, 2, 2, 2, 185, 18461, 1842626, 183987603, 1837682236, 1999303871, 2000827643, 2000777468, 2000722020, 2000673854, 2000631711, 2000594530, 2000561482, 2000531914, 2000505305, 2000481231, 2000459347, 2000439367

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Example

a(6) = floor(121110987/654321) = floor(185.094146451053840546153951959359) = 185.

Mathematica

f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[2n - k + 1]]; y = StringJoin[ToString[2k - 1], y]; k++ ]; Return[ Floor[10* ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
  fd[st_, en_]:=FromDigits[Flatten[IntegerDigits/@Range[st, en, -1]]]; Table[ Floor[fd[2n, n+1]/fd[n, 1]], {n, 30}] (* Harvey P. Dale, Jul 04 2013 *)

Crossrefs

Cf. A067088.

Sequence in context: A057331 A334053 A270374 * A339027 A343121 A090872

Adjacent sequences: A067086 A067087 A067088 * A067090 A067091 A067092

Keyword

easy,base,nonn

Author

Amarnath Murthy, Jan 07 2002

Extensions

More terms from Robert G. Wilson v, Jan 09 2002

Offset corrected by Sean A. Irvine, Dec 02 2023

Status

approved