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%I #15 Dec 02 2023 23:17:08
%S 2,3,5,7,8,981,114462,13082645,1471900839,1635537203,1799173568,
%T 1962809933,2126446298,2290082663,2453719028,2617355393,2780991758,
%U 2944628123,3108264488,3271900853,3435537218,3599173583,3762809948
%N Floor(X/Y) where X = concatenation of (2n), (2n-1), ... down to n+1 and Y = concatenation of 1,2,3,... up to n.
%e a(4) = floor(8765/1234) = 7.
%e a(6) = floor(121110987/123456) = floor(981.00527313374805598755832037325) = 981.
%t 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} ]
%t Table[Floor[FromDigits[Flatten[IntegerDigits/@(Range[2n,n+1,-1])]]/FromDigits[Flatten[IntegerDigits/@(Range[n])]]],{n,25}] (* _Harvey P. Dale_, Jul 24 2011 *)
%Y Cf. A067088, A067089.
%K easy,base,nonn
%O 1,1
%A _Amarnath Murthy_, Jan 07 2002
%E More terms from _Robert G. Wilson v_, Jan 09 2002
%E Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, May 14 2007
%E Offset corrected by _Sean A. Irvine_, Dec 02 2023