L.g.f.: log(Sum_{k>=0} k! * x^(k*(k + 1)/2) / Product_{j=1..k} (1 - x^j)).

Terms

a(0) =1a(1) =1a(2) =7a(3) =1a(4) =11a(5) =25a(6) =15a(7) =17a(8) =-11a(9) =241a(10) =-87a(11) =217a(12) =-467a(13) =645a(14) =707a(15) =-159a(16) =35a(17) =-1451a(18) =4067a(19) =-9679a(20) =17661a(21) =-19755a(22) =42413a(23) =-55615a(24) =31061a(25) =-59799a(26) =28231a(27) =147841a(28) =-230549a(29) =473185