2,1

If n is prime, then n divides c(n). If n is composite and divides c(n) it is a pseudoprime to both the Lucas (Bruckman) and Perrin tests, which is the intersection of A005845 and A013998.

Conjecture: Records of the sequence are consecutive primes.

Table of n, a(n) for n=2..90.

Cf. A000032, A001608, A178380, A005845, A013998.

Sequence in context: A099636 A099635 A178380 * A086847 A098228 A081303

Adjacent sequences: A178372 A178373 A178374 * A178376 A178377 A178378

nonn

Vladimir Shevelev, May 26 2010

More terms from R. J. Mathar, Aug 08 2010

approved