%I #14 Dec 02 2023 23:17:03

%S 2,2,329,4101,4919,5737,6556,7374,8193,9012,9830,10649,11467,12286,

%T 13104,13923,14741,15560,16378,17197,18015,18834,19652,20471,212899,

%U 22108437,2292696195,237454867452,24564011532104,2538253631893694

%N Floor(X/Y) where X = concatenation of the (n+1)-st even number through the (2n)-th even number and Y = concatenation of first n even numbers.

%H Hans Havermann, <a href="http://chesswanks.com/seq/a067091">First 1000 terms</a>

%e a(4) = floor(10121416/2468) = floor(4101.05996758508914100486223662885) = 4101.

%e a(7) = floor(16182022242628/2468101214) = floor(6556.4662222268166673) = 6556.

%t z[n_] := Block[{a = "", m = n}, While[ Length[m] > 0, a = StringJoin[a, ToString[m[[1]]]]; m = Drop[m, 1]]; ToExpression[a]]; Table[ Floor[ z[Table[2i, {i, n + 1, 2n}]] / z[ Table[2i, {i, 1, n}]]], {n, 1, 30}]

%Y Cf. A067088, A067089, A067090.

%K easy,base,nonn

%O 1,1

%A _Amarnath Murthy_, Jan 07 2002

%E Edited by _N. J. A. Sloane_ and _Robert G. Wilson v_, Jun 14 2002