0,3

The case n=1 is exceptional, and a(1) could be 0 or 1.

Yu. I. Manin, Rational surfaces and Galois cohomology, pp. 495-509 of Proc. International Congress Mathematicians, Moscow 1966.

M. Nagata, On rational surfaces, I, II, Mem. Coll. Sci. Univ. Kyoto, Ser. A., XXXII (No. 3, 1960) and XXXIII (No. 2, 1960).

Sequence in context: A054886 A130578 A107068 this_sequence A038505 A119971 A094272

Adjacent sequences: A033538 A033539 A033540 this_sequence A033542 A033543 A033544

fini,full,nonn

njas, Feb 13 2002