A084039 a(1) = 1; then distinct numbers such that both the product of two successive terms + 1 and the ratio of the larger to the smaller of two successive terms + 1 is a prime.

1, 2, 8, 32, 384, 4608, 4, 24, 48, 12, 3, 6, 72, 18, 9, 54, 27, 108, 1296, 648, 324, 162, 2916, 34992, 979776, 7, 28, 112, 448, 8064, 1344, 224, 14, 252, 63, 756, 21, 42, 84, 504, 1008, 12096, 96, 192, 768, 1536, 9216, 16, 480, 30, 5, 20, 80, 320, 5760, 10, 40

Offset

1,2

Comments

a(k+1) is either a multiple or a divisor of a(k).

Links

Table of n, a(n) for n=1..57.

Example

8 follows 2 as both 2*8 + 1 = 17 and 8/2 + 1 = 5 are primes.

Crossrefs

Cf. A084040, A084041.

Sequence in context: A139014 A063505 A085466 * A135620 A134708 A294530

Adjacent sequences: A084036 A084037 A084038 * A084040 A084041 A084042

Keyword

nonn

Author

Amarnath Murthy, May 26 2003

Extensions

Corrected and extended by Ray Chandler, Aug 05 2003

Status

approved