I have an IRanges object SEQ:

     rs60733400        1   [2516781, 2516781]      *   |         <NA>              G                  A
        rs876938        1   [2523212, 2523212]      *   |         <NA>              G                  C
        rs867435        1   [2523706, 2523706]      *   |         <NA>              C                  T
        rs867436        1   [2523723, 2523723]      *   |         <NA>              C                  T
      rs10752747        1   [2524915, 2524915]      *   |         <NA>              G                  T
             ...      ...                  ...    ... ...          ...            ...                ...
        rs137688       22 [39741091, 39741091]      *   |         <NA>              G                  A
        rs137685       22 [39739628, 39739628]      *   |         <NA>              C                  T
      rs62323904        X [58426952, 58426952]      *   |         <NA>              T                  G
      rs72834512        X [79371195, 79371195]      *   |         <NA>              T                  C
       rs3000483        Y [ 3631240,  3631240]      *   |         <NA>              T                A,C

I want to extract for every rs... a corresponding seqname. In the end I want to have a vector with a seqname of the same length as names(SEQ).

I tried seqnames(SEQ) but it gives me a factor-Rle of length 2040 with 24 runs, but I have no idea how to extract "Values" parameter from there.