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math.CO2023
Enumeration of flattened -Stirling permutations with respect to descents
Umesh Shankar
A -Stirling permutation of order is said to be "flattened" if the leading terms of its increasing runs are in ascending order. We show that flattened -Stirling permutatio…
math.CO2022
-enumeration of type B and D Eulerian polynomials based on parity of descents
Hiranya Kishore Dey, Umesh Shankar, Sivaramakrishnan Sivasubramanian
Carlitz and Scoville in 1973 considered a four variable polynomial that enumerates permutations in with respect to the parity of its descents and ascents. In recen…