A086553 a(1) = 1, a(n) = smallest number not included earlier such that both a(n) + 1 and a(n)*a(n-1) + 1 are primes.

1, 2, 6, 10, 4, 18, 22, 16, 12, 28, 36, 46, 30, 40, 52, 60, 42, 58, 72, 88, 112, 66, 70, 82, 78, 96, 100, 106, 130, 126, 102, 136, 148, 162, 108, 166, 180, 138, 156, 172, 150, 178, 250, 190, 210, 196, 192, 228, 240, 198, 280, 226, 232, 238, 222, 268, 282, 306, 262

Offset

0,2

Comments

Conjecture: every number p-1 is a term for all primes p.

Links

Table of n, a(n) for n=0..58.

Crossrefs

Sequence in context: A052194 A320383 A073662 * A342068 A004055 A077933

Adjacent sequences: A086550 A086551 A086552 * A086554 A086555 A086556

Keyword

nonn

Author

Amarnath Murthy, Aug 29 2003

Extensions

More terms from David Wasserman, Mar 25 2005

Status

approved