A067090 Floor(X/Y) where X = concatenation of (2n), (2n-1), ... down to n+1 and Y = concatenation of 1,2,3,... up to n.

2, 3, 5, 7, 8, 981, 114462, 13082645, 1471900839, 1635537203, 1799173568, 1962809933, 2126446298, 2290082663, 2453719028, 2617355393, 2780991758, 2944628123, 3108264488, 3271900853, 3435537218, 3599173583, 3762809948

Offset: 1

Author

Amarnath Murthy, Jan 07 2002

Keywords

• easy
• base
• nonn

Examples

			a(4) = floor(8765/1234) = 7.
a(6) = floor(121110987/123456) = floor(981.00527313374805598755832037325) = 981.
		

Crossrefs

Cf. A067088, A067089.

Programs

Mathematica

f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[2n - k + 1]]; y = StringJoin[y, ToString[2k - 1]]; k++ ]; Return[ Floor[ ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
Table[Floor[FromDigits[Flatten[IntegerDigits/@(Range[2n,n+1,-1])]]/FromDigits[Flatten[IntegerDigits/@(Range[n])]]],{n,25}] (* Harvey P. Dale, Jul 24 2011 *)

Extensions

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

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 14 2007

Offset corrected by Sean A. Irvine, Dec 02 2023