493209domain: NAppears in sequencesE.g.f. sinh(log(1+x))/exp(x). Unsigned sequence gives degrees of (finite by nilpotent) representations of Braid groups.at n=9A009578Number of (n+1)X(n+1) -7..7 symmetric matrices with every 2X2 subblock having sum zero and one or three distinct values.at n=13A211443