Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| No. in series | No. in season | Title | Directed by | Written by | Original air date | Production code | U.S. viewers (million) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 47.0 | 1.0 | "Red Sky at Night" | Chris Long | Bruno Heller | September23,2010 | 3X6401 | 15.50 |
| 48.0 | 2.0 | "Cackle-Bladder Blood" | John Polson | Ashley Gable | September30,2010 | 3X6402 | 14.65 |
| 49.0 | 3.0 | "The Blood on His Hands" | David M. Barrett | Tom Szentgyorgyi | October7,2010 | 3X6403 | 14.39 |
| 50.0 | 4.0 | "Red Carpet Treatment" | Charles Beeson | Daniel Cerone | October14,2010 | 3X6404 | 15.13 |
| 51.0 | 5.0 | "The Red Ponies" | John F. Showalter | Eoghan Mahony | October21,2010 | 3X6405 | 14.42 |
| 52.0 | 6.0 | "Pink Chanel Suit" | Eric Laneuville | Ken Woodruff | October28,2010 | 3X6406 | 14.76 |
| 53.0 | 7.0 | "Red Hot" | Chris Long | Ashley Gable | November4,2010 | 3X6407 | 14.42 |
| 54.0 | 8.0 | "Ball of Fire" | Stephen Gyllenhaal | Tom Szentgyorgyi | November11,2010 | 3X6408 | 13.84 |
| 55.0 | 9.0 | "Red Moon" | Simon Baker | Bruno Heller | November18,2010 | 3X6409 | 14.74 |
| 56.0 | 10.0 | "Jolly Red Elf" | John F. Showalter | Daniel Cerone | December9,2010 | 3X6410 | 13.41 |
| 57.0 | 11.0 | "Bloodsport" | Roxann Dawson | Eoghan Mahony | January6,2011 | 3X6411 | 14.88 |
| 58.0 | 12.0 | "Bloodhounds" | Charles Beeson | Erika Green Swafford | January20,2011 | 3X6412 | 14.82 |
| 59.0 | 13.0 | "Red Alert" | Guy Ferland | Jordan Harper | February3,2011 | 3X6413 | 15.18 |
| 60.0 | 14.0 | "Blood for Blood" | Martha Mitchell | David Appelbaum | February10,2011 | 3X6414 | 14.86 |
| 61.0 | 15.0 | "Red Gold" | Tom Verica | Cindi M. Grossenbacher | February17,2011 | 3X6415 | 15.01 |
| 62.0 | 16.0 | "Red Queen" | Chris Long | Daniel Cerone | February24,2011 | 3X6416 | 14.79 |
| 63.0 | 17.0 | "Bloodstream" | Bobby Roth | Erika Green Swafford | March10,2011 | 3X6417 | 14.28 |
| 64.0 | 18.0 | "The Red Mile" | Darnell Martin | Tom Szentgyorgyi | March31,2011 | 3X6418 | 14.27 |
| 65.0 | 19.0 | "Every Rose Has Its Thorn" | Charles Beeson | Ken Woodruff | April7,2011 | 3X6419 | 15.17 |
| 66.0 | 20.0 | "Redacted" | David M. Barrett | Eoghan Mahony | April28,2011 | 3X6420 | 13.53 |
| 67.0 | 21.0 | "Like a Redheaded Stepchild" | Eric Laneuville | Jordan Harper | May5,2011 | 3X6421 | 14.00 |
| 68.0 | 22.0 | "Rhapsody in Red" | David M. Barrett | David Appelbaum | May12,2011 | 3X6422 | 14.07 |
| 69.0 | 23.0 | " Strawberries and Cream (Part 1) " | Chris Long | Ashley Gable | May19,2011 | 3X6423 | 14.11 |
Question:
What was the production code of the episode no. 55 in the series?
Answer:
3X6409