A262539 a(n) = coefficient of x^n in the expansion of Product_{k>=1} (1-x^k)^(3*n).
1, -3, 9, -12, -99, 1107, -7038, 33345, -113643, 151593, 1547469, -17376120, 112734378, -544200660, 1884830229, -2551628817, -26299018683, 298555990425, -1956243650733, 9538198578972, -33464928293199, 47571625958796, 452674080810576, -5260288747038957, 34841458485708282, -171603777320158968
Offset: 0
Keywords
Programs
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Maple
C3:=proc(k) local t1,n; t1:=mul((1-x^n)^(3*k),n=1..k+2); series(t1,x,k+1); coeff(%,x,k); end; [seq(C3(i),i=0..30)];