OFFSET
1,2
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..1356
MATHEMATICA
a[n_] := a[n] = Block[{s = Sum[a[i]*x^i, {i, 0, n - 1}]}, If[ IntegerQ@ Last@ CoefficientList[ Series[ Sqrt[s + x^n], {x, 0, n}], x], 1, 2]]; Union@ Table[ If[ a[n] == 1, n, 0], {n, 0, 300}] (* Robert G. Wilson v, Nov 25 2006 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, following a suggestion from Paul D. Hanna, Jun 30 2005
STATUS
approved