a(n) = [x^(n*(n+1)*(2*n+1)/6)] Product_{k=1..n} Sum_{m>=0} x^(k^2*m).

A321186

a(n) = [x^(n*(n+1)*(2*n+1)/6)] Product_{k=1..n} Sum_{m>=0} x^(k^2*m).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =25a(5) =123a(6) =683a(7) =4083a(8) =25839a(9) =171324a(10) =1178755a(11) =8362768a(12) =60867478a(13) =452760486a(14) =3431366195a(15) =26430813268a(16) =206504120774

External references