We confirm a conjecture of Lara Pudwell and show that permutations of [n] that avoid the barred pattern bar{ 3}bar{ 1}542 are counted by OEIS sequence A047970. In fact, we show bijectively that the number of bar{ 3}bar{ 1}542 avoiders of length n with j+k left-to-right maxima, of which j initiate a descent in the permutation and k do not, is { n}-choose-{ k} j! StirlingPartition{ n-j-k}{ j}, where StirlingPartition{ n}{ j} is the Stirling partition number.
Categories: math.CO