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%I #10 Aug 07 2015 03:11:31
%S 0,1,2,12,13,23,123,124,134,234,1234,1235,1245,1345,2345,12345,12346,
%T 12356,12456,13456,23456,123456,123457,123467,123567,124567,134567,
%U 234567,1234567,1234568,1234578,1234678,1235678,1245678,1345678,2345678
%N Triangle read by rows in which the n-th row contains the n numbers in increasing order formed by the concatenation of first n-1 numbers. (The digits of the numbers with 2 or more digits are taken as one entity.) First row is taken to be 0.
%e 0; 1,2; 12,13,23; 123,124,134,234; 1234,1235,1245,1345,2345; 12345,12346, ...
%p conca := proc(S) local resul,d,i ; resul := 0 ; for i from 1 to nops(S) do d := ilog10(op(i,S))+1 ; resul := resul*10^d+op(i,S) ; od ; resul ; end: A081539 := proc(row) local a,p,i; if row =1 then RETURN([0]) ; fi ; a := [] ; p := [seq(i,i=1..row)] ; for i from 1 to row do a := [op(a),conca(subsop(i=NULL,p))] ; od: sort(a)[1..row] ; end: for n from 1 to 10 do op(A081539(n)) ; od ; # _R. J. Mathar_, Jul 15 2007
%Y Cf. A081540.
%K nonn,base,tabl
%O 1,3
%A _Amarnath Murthy_, Mar 29 2003
%E More terms from _R. J. Mathar_, Jul 15 2007
%E Edited by _Charles R Greathouse IV_, Apr 30 2010
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