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%I #7 Jul 15 2017 18:42:29
%S 1,1,1,11,110,1102,11024,110242,1102422,1102422,1102422,1102422,
%T 1102422,11024223,110242233,1102422331,11024223315,110242233152,
%U 1102422331526,11024223315266,110242233152667,1102422331526679
%N Floor(X/Y), where X = concatenation of the triangular numbers and Y = concatenation of natural numbers.
%C a(n) -> 11024223315266792255432504568329867353511401594905438085....
%t f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[k(k+1)/2]]; y = StringJoin[y, ToString[k]]; k++ ]; Return[ Floor[ ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
%t Module[{nn=30,trs,nts},trs=IntegerDigits/@Accumulate[Range[nn]];nts= IntegerDigits/@ Range[nn];Table[Floor[ FromDigits[Flatten[ Take[trs,n]]]/ FromDigits[ Flatten[ Take[nts,n]]]],{n,nn}]] (* _Harvey P. Dale_, Jul 15 2017 *)
%Y Cf. A007908.
%K nonn,base,less
%O 1,4
%A _Robert G. Wilson v_, Jan 09 2002
%E Edited by _Charles R Greathouse IV_, Apr 28 2010
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