%I #6 Dec 05 2013 19:55:07
%S 2,1,1,1,19,190,1909,19092,190926,190926,190926,190926,190926,190926,
%T 190926,190926,190926,190926,190926,190926,190926,190926,190926,
%U 190926,190926,1909260,19092601,190926018,1909260182,19092601827,190926018273
%N Floor[ X/Y], where X = concatenation of the primes and Y = concatenation of natural numbers.
%e a(5) = floor [235711/12345]=floor[19.093641150...] = 19.
%t f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[Prime[k]]]; y = StringJoin[y, ToString[k]]; k++ ]; Return[ Floor[ ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
%t nn=40;With[{prs=Prime[Range[nn]],nats=Range[nn]},Table[Floor[FromDigits[ Flatten[IntegerDigits/@Take[prs,n]]]/FromDigits[Flatten[IntegerDigits /@Take[nats,n]]]],{n,nn}]] (* _Harvey P. Dale_, Mar 24 2012 *)
%Y Cf. A067091, A067092, A067093, A067094, A067095, A067096, A067097, A067098, A067099.
%Y floor[A019518(n)/A007908(n)]
%K easy,base,nonn
%O 1,1
%A _Amarnath Murthy_, Jan 07 2002
%E More terms from _Robert G. Wilson v_, Jan 09 2002