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%I #11 Jul 22 2022 13:20:06
%S 1,4,20,123,823,5878,44091,342935,2743484,224466889,18705574106,
%T 1582779347450,135666801210013,11757789438201155,1028806575842601095,
%U 90777050809641273099,8069071183079224275500,721969526907088487807963
%N Floor(decimal concatenation of first n natural numbers/their sum).
%H Harry J. Smith, <a href="/A067116/b067116.txt">Table of n, a(n) for n = 1..100</a>
%e a(6) = floor (123456 / 21) = 5878.
%t Table[Floor[FromDigits[Flatten[IntegerDigits/@Range[n]]]/Total[Range[n]]],{n,20}] (* _Harvey P. Dale_, Jul 22 2022 *)
%o (PARI) digitsIn(x)= { local(d); if (x==0, return(1)); d=1 + log(x)\log(10); if (10^d == x, d++, if (10^(d-1) > x, d--)); return(d) } Concat(a, b)= { return(a*10^digitsIn(b) + b) } { c=0; s=0; for (n=1, 100, c=Concat(c, n); s+=n; write("b067116.txt", n, " ", floor(c/s)) ) } \\ _Harry J. Smith_, May 24 2010
%K easy,nonn,base
%O 1,2
%A _Amarnath Murthy_, Jan 08 2002
%E More terms from several contributors
%E Edited by _Charles R Greathouse IV_, Apr 26 2010
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