How to convert output in traditional format into text and replace spaces with *?

Question

From a following program (part of a longer program) I will get a recurrence in an elegant format.

 sold =
 {624, -1490, 1244, -430, 52, 0, 0, 0, 0, 0, 0, -6648, 13539, -9945, 
 3117, -351, 0, 0, 0, 0, 0, 0, 12384, -22716, 15216, -4416, 468, 0, 
 0, 0, 0, 0, 0, 3456, -8672, 6752, -2032, 208, 0, 0, 0, 0, 0, 0, 
 53760, -86912, 47552, -10624, 832, 0, 0, 0, 0, 0, 0};
 maxdenom = 624; maxdeg = 10; j = 4;
 strecur = ""; ikoef = 0;
 Do[sign = 0; dejmin = 0; numpol = Factor[Sum[ikoef++; 
  If[sold[[ikoef]] != 0, sign = Sign[sold[[ikoef]]]];
  sold[[ikoef]]*n^i, {i, 0, maxdeg}]];
  If[ord == 0, signan = sign; 
  If[signan < 0, numpol = -numpol; sign = 1;]];
  If[ord > 0 && signan > 0, If[sign == 1, dejmin = 1, 
  If[sign != 0, numpol = Factor[-numpol]; sign = 1];];];
  If[ord > 0 && signan < 0, 
  If[sign == -1, dejmin = 1; numpol = Factor[-numpol]; sign = 1];];
  strpol = ToString[TraditionalForm[numpol*a[n - ord]]];
  If[sign == 1, If[ord < 2, znam = "", znam = "+"], 
  If[ord > 1, znam = "+", znam = ""]];
  If[dejmin == 1, znam = "-"];
  If[sign != 0 && strpol != "0", strecur = strecur <> znam <> strpol];
  If[ord == 0, strecur = strecur <> "="];, {ord, 0, j}];
 Print[strecur]

How to replace spaces with * in the TraditionalForm output ? I can export this (manually) as "plain text"

 2 (n-1) (2 n-3) (13 n^2-75 n+104) a(n)=3 (117 n^4-1039 n^3+3315 n^2-4513 n+2216) a(n-1)-12 (39 n^4-368 n^3+1268 n^2-1893 n+1032) a(n-2)-16 (n-4) (13 n^3-75 n^2+122 n-54) a(n-3)-64 (n-5) (n-4) (13 n^2-49 n+42) a(n-4)

and replace all spaces with * manually in an external editor. But I want to do this in Mathematica and print it (with *) inside the program. I need a string

 "2*(n-1)*(2*n-3)*(13*n^2-75*n+104)*a(n)=3*(117*n^4-1039*n^3+3315*n^2-4513*n+2216)*a(n-1)-12*(39*n^4-368*n^3+1268*n^2-1893*n+1032)*a(n-2)-16*(n-4)*(13*n^3-75*n^2+122*n-54)*a(n-3)-64*(n-5)*(n-4)*(13*n^2-49*n+42)*a(n-4)"

After

 ToString[strecur]

I get an absolutelly unusable output with exponents on separate lines.

So, my question is: How to convert it from a traditional format to a string (without changing the order of terms) ? Then it's easy to do StringReplace["string", " " -> "*"]

Answer 1

Change the line starting with strpol to

strpol = ToString[numpol*a[n - ord] /. Times -> Inactive[Times], TraditionalForm]

and you should get output like the following (click on the image to enlarge):

Answer 2

I find a clear solution of my problem. After the conversion with ToString, the following program merges two lines with the exponents back to one line. Then is the final expression in the required format and it's possible to replace spaces with *.

 line1 = Characters[StringSplit[ToString[strecur], "\n"][[1]]];
 line2 = Characters[StringSplit[ToString[strecur], "\n"][[2]]];
 formula = ""; Do[If[k <= Length[line1], 
 If[line1[[k]] != " ", formula = formula <> "^" <> line1[[k]], 
 formula = formula <> line2[[k]];], 
 formula = formula <> line2[[k]];], {k, 1, Length[line2]}];
 formula = StringReplace[formula, "+ " -> "+"];
 formula = StringReplace[formula, " +" -> "+"];
 formula = StringReplace[formula, "- " -> "-"];
 formula = StringReplace[formula, " -" -> "-"];
 formula = StringReplace[formula, " " -> "*"]

 (* "2*(n-1)*(2*n-3)*(13*n^2-75*n+104)*a(n)=3*(117*n^4-1039*n^3+3315*n^2-4513*n+2216)*a(n-1)-12*(39*n^4-368*n^3+1268*n^2-1893*n+1032)*a(n-2)-16*(n-4)*(13*n^3-75*n^2+122*n-54)*a(n-3)-64*(n-5)*(n-4)*(13*n^2-49*n+42)*a(n-4)" *)

Answer 3

The best way would be to convert strecur into a Mathematica expression

exrecur=ToExpression[StringReplace[strecur, "=" -> "=="]

You need to replace "=" with "==" because you don't want to make an assignment. Next just convert it back to string using the InputForm

strecurInput = ToString[exrecur,InputForm]

Similarly as above you can replace back "==" with "=" if you like to.