Coefficient of x^n in the expansion of ( (1-x) / (1-x-x^2) )^(3*n).

A370623

Coefficient of x^n in the expansion of ( (1-x) / (1-x-x^2) )^(3*n).

Terms

    a(0) =1a(1) =0a(2) =6a(3) =9a(4) =90a(5) =255a(6) =1671a(7) =6258a(8) =34674a(9) =148455a(10) =765141a(11) =3499551a(12) =17487531a(13) =82704921a(14) =408192420a(15) =1964826174a(16) =9657348546a(17) =46944246777a(18) =230604062127

External references