A224221 a(0)=3; for n>0, a(n) is the smallest odd prime q not already in the sequence such that the n-th prime p(n) divides a(n-1)+q. If no such prime q exists, the sequence terminates.

3, 5, 7, 13, 29, 37, 41, 61, 53, 131, 43, 19, 277, 379, 137, 239, 79, 157, 331, 71

Offset

0,1

Comments

a(20) does not exist, so the sequence terminates. A134204 is a similar sequence for which the termination question is unresolved.

Links

Table of n, a(n) for n=0..19.

Example

After a(3)=13, to find a(4) we look for an odd prime q such that the fourth prime, 7, divides 13+q, and q=29 works, since 7 divides 13+29 = 42.
After a(19)=71 we look for an odd prime q such that p(20)=71 divides 71+q. The only candidate is q=71. Since 71 is already in the sequence, the sequence terminates.

Crossrefs

Cf. A134204, A224222.

Sequence in context: A257762 A374761 A224222 * A128547 A087383 A038928

Adjacent sequences: A224218 A224219 A224220 * A224222 A224223 A224224

Keyword

nonn,fini,full

Author

Daniel Drucker and N. J. A. Sloane, Apr 05 2013

Status

approved