A111630 - OEIS

%I #4 Mar 30 2012 18:36:50

%S 1,1,1,2,1,2,2,3,1,1,3,2,2,1,1,1,3,2,2,3,3,1,2,3,3,2,1,3,3,1,2,1,2,2,

%T 3,2,1,2,2,2,1,1,1,1,2,3,3,1

%N T(3n, 3n-2)/n of A109626.

%C A sequence of just 1's, 2's and 3's.

%t f[n_] := f[n] = Block[{a}, a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[ a[i]*x^i, {i, 0, l - 1}]}, While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/n), {x, 0, l}], x]]] != True, k++ ]; k]; Table[a[j], {j, 0, 128}]]; g[n_, m_] := f[n][[m]]; Table[ g[3n, 3n - 2]/n, {n, 48}]

%Y Cf. A109626.

%K nonn

%O 1,4

%A _Paul D. Hanna_ and _Robert G. Wilson v_, Aug 02 2005