Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 4500 articles have referenced us, often saying "we would not have discovered this result without the OEIS".
Table of n, a(n) for n=1..28.
a(11)=12207031 because C11(x) is composite for x=2,3,4 and C11(5)=12207031 is prime.
Cf. A084732, A085398.
Sequence in context: A051860 A155766 A153488 * A063696 A258126 A069587
Adjacent sequences: A085396 A085397 A085398 * A085400 A085401 A085402
Don Reble (djr(AT)nk.ca), Jun 28 2003