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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: A155766 A153488 A275115 * A063696 A258126 A069587
Adjacent sequences: A085396 A085397 A085398 * A085400 A085401 A085402
Don Reble (djr(AT)nk.ca), Jun 28 2003