A300191 Look and Say the digits of the last three terms, by increasing digit value. Start with a(1)=1, a(2)=2 and a(3)=3.
1, 2, 3, 111213, 412223, 51423314, 7152433415, 515253543517, 613263548527, 5142634495263718, 515263549546372819, 516263648566373839, 515283648596374849, 414283649596376859, 3132837475106377869, 10413283746576677869, 20513283644596976859, 30514283545596976859
Offset: 1
Examples
1, 2, 3 => there are one '1', one '2' and one '3': 111213; 2, 3, 111213 => there are four '1', two '2' and two '3': 412223; 3, 111213, 412223 => there are five '1', four '2', three '3', one '4': 51423314.
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Programs
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Maple
P:=proc(q) local a,b,c,d,k,n,y,x; y:=array(1..3); x:=array(0..9); y[1]:=1; y[2]:=2; y[3]:=3; print(1); print(2); print(3); a:=[]; b:=[1]; c:=[2]; for n from 1 to q do for k from 0 to 9 do x[k]:=0; od; a:=b; b:=c; c:=convert(y[3],base,10); for k from 1 to nops(a) do x[a[k]]:=x[a[k]]+1; od; for k from 1 to nops(b) do x[b[k]]:=x[b[k]]+1; od; for k from 1 to nops(c) do x[c[k]]:=x[c[k]]+1; od; y[1]:=y[2]; y[2]:=y[3]; y[3]:=0; for k from 0 to 9 do if x[k]>0 then if k=0 then d:=10*x[k]; else d:=10*x[k]+k; fi; y[3]:=y[3]*10^(ilog10(d)+1)+d; fi; od; print(y[3]); od; end: P(10^2);
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Mathematica
Nest[Append[#, FromDigits[Join @@ Map[Flatten@ Reverse@ # &, IntegerDigits@ Sort@ Tally[Join @@ IntegerDigits[#[[-3 ;; -1]]]]]]] &, {1, 2, 3}, 15] (* Michael De Vlieger, Mar 01 2018 *)
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