DOUBLOONS AND NEW Q-TANGENT NUMBERS

D. Foata, G.-N. Han
2009 Quarterly Journal of Mathematics  
We introduce new q-tangent numbers based on the Carlitz q-analog of the Eulerian polynomial and the so-called doubloon combinatorial set-up. Those new q-tangent numbers are polynomials with positive integral coefficients. They are divisible by products of binomials of the form 1 + q i , the quotients being q-analogs of the reduced tangent numbers having an explicit combinatorial interpretation.
doi:10.1093/qmath/hap043 fatcat:zlvkyarlvnelvf7hs7a46cse6q