A111614 First upper diagonal of array in A109626.

1, 1, 1, 3, 1, 6, 1, 7, 1, 3, 1, 6, 1, 3, 12, 3, 1, 6, 1, 11, 18, 3, 1, 24, 1, 3, 1, 8, 1, 21, 1, 11, 20, 20, 23, 16, 1, 22, 34, 21, 1, 14, 1, 22, 24, 26, 1, 2, 1, 43, 6, 26, 1, 33, 17, 46, 43, 32, 1, 25, 1, 34, 47, 35, 63, 25, 1, 8, 49, 31, 1, 48, 1, 40, 32, 73, 21, 58, 1, 80, 28, 44, 1, 29

Offset

1,4

Comments

a(1) = a(2) = 1 and a(p^e) = 1 for odd primes p and noncomposite exponents e.

a(81) = 28 and not 1 because 9^2 = 81.

Links

Table of n, a(n) for n=1..84.

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, 128}]]; g[n_, m_] := f[n][[m]]; Table[ g[n, n + 1], {n, 84}]

Crossrefs

Cf. A109626.

Sequence in context: A040011 A066446 A069625 * A193279 A076889 A134689

Adjacent sequences: A111611 A111612 A111613 * A111615 A111616 A111617

Keyword

nonn

Author

Paul D. Hanna and Robert G. Wilson v, Jul 30 2005

Status

approved