A111603 Consider the array T(n, m) where the n-th row is the sequence of integer coefficients of A(x), where 1<=a(n)<=n, such that A(x)^(1/n) consists entirely of integer coefficients and where m is the (m+1)-th coefficient. This is the antidiagonal read from upper right to lower left.
1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 2, 3, 4, 1, 1, 2, 1, 2, 5, 1, 1, 2, 3, 4, 5, 6, 1, 1, 1, 3, 3, 5, 3, 7, 1, 1, 2, 3, 4, 5, 2, 7, 8, 1, 1, 2, 3, 4, 1, 3, 7, 4, 9, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 1, 1, 3, 1, 5, 6, 7, 2, 3, 5, 11, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 1, 1, 3, 4, 5, 3, 1, 4, 9, 10
Offset: 1
Examples
Table begins k= 0 1 2 3 4 5 6 7 8 9 10 11 12 13 n\ 1| 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2| 1 2 1 2 2 2 1 2 2 2 1 2 1 2 3| 1 3 3 1 3 3 3 3 3 3 3 3 1 3 4| 1 4 2 4 3 4 4 4 1 4 4 4 3 4 5| 1 5 5 5 5 1 5 5 5 5 4 5 5 5 6| 1 6 3 2 3 6 6 6 3 4 6 6 6 6 7| 1 7 7 7 7 7 7 1 7 7 7 7 7 7 8| 1 8 4 8 2 8 4 8 7 8 8 8 4 8 9| 1 9 9 3 9 9 3 9 9 1 9 9 6 9 10| 1 10 5 10 10 2 5 10 10 10 3 10 5 10 11| 1 11 11 11 11 11 11 11 11 11 11 1 11 11 12| 1 12 6 4 9 12 4 12 12 8 6 12 6 12 13| 1 13 13 13 13 13 13 13 13 13 13 13 13 1 14| 1 14 7 14 7 14 14 2 7 14 14 14 14 14 15| 1 15 15 5 15 3 10 15 15 10 15 15 5 15 16| 1 16 8 16 4 16 8 16 10 16 8 16 12 16
Crossrefs
Programs
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Mathematica
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, 32}]]; g[n_, m_] := f[n][[m]]; Flatten[ Table[ f[i, n - i], {n, 15}, {i, n - 1, 1, -1}]]
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