Expansion of 1/(1 - 2*x - 21*x^2).

Terms

a(0) =1a(1) =2a(2) =25a(3) =92a(4) =709a(5) =3350a(6) =21589a(7) =113528a(8) =680425a(9) =3744938a(10) =21778801a(11) =122201300a(12) =701757421a(13) =3969742142a(14) =22676390125a(15) =128717365232a(16) =733638923089