Symmetrical triangle T(n, m) = floor(Eulerian(n+1, m)/2), read by rows.

Terms

a(0) =2a(1) =5a(2) =5a(3) =13a(4) =33a(5) =13a(6) =28a(7) =151a(8) =151a(9) =28a(10) =60a(11) =595a(12) =1208a(13) =595a(14) =60a(15) =123a(16) =2146a(17) =7809a(18) =7809a(19) =2146a(20) =123a(21) =251a(22) =7304a(23) =44117a(24) =78095a(25) =44117a(26) =7304a(27) =251a(28) =506a(29) =23920