Coefficient of x^n in the expansion of ( (1+x)^3 + x^3 )^n.

A370287

Coefficient of x^n in the expansion of ( (1+x)^3 + x^3 )^n.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =87a(4) =531a(5) =3333a(6) =21309a(7) =138015a(8) =902547a(9) =5946153a(10) =39406005a(11) =262404585a(12) =1754316045a(13) =11767931451a(14) =79165530375a(15) =533883963567

External references