43643domain: NAppears in sequencesa(n) = 121*n^2 - 2*n.at n=18A157040Number of (n+1)X(n+1) -6..6 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.at n=4A211259Cogrowth sequence of the 12-element dicyclic group Dic12 = <S,T | S^6, T^4, STST^3, S^3T^2>.at n=19A377656