A086208 Prime numbers p with the property that the sequence p-1*2, p-2*3, p-3*4, p-4*5, ..., consists only of primes and a final 1.

3, 7, 13, 43, 73

Offset

0,1

Comments

Related to the fact that the list 5, 8, 13, 29, 53, 173, 293 gives the only positive discriminants of class number 1 of the form j^2+1.

If we allow the first number that we subtract to be greater than 2, the next sequence after 73, 71, 67, 61,... is 2003, 1831, 1657, 1481, 1303, 1123, 941, 757, 571, 383, 193, 1: start with 2003 and subtract 172,174,176, etc., which is an amusing property of 2003.

Links

Table of n, a(n) for n=0..4.

Example

For example 73 71 67 61 53 43 31 17 1. If the GRH is true this is the last example.

Crossrefs

Sequence in context: A191974 A174241 A289556 * A090968 A020641 A358547

Adjacent sequences: A086205 A086206 A086207 * A086209 A086210 A086211

Keyword

nonn,fini,full

Author

Maurice Mischler (maurice.mischler(AT)ima.unil.ch), Aug 27 2003

Extensions

Definition corrected by Harvey P. Dale, Jul 25 2015

Status

approved