login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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. 0

%I #4 Jul 25 2015 14:03:52

%S 3,7,13,43,73

%N 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.

%C 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.

%C 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.

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

%K nonn,fini,full

%O 0,1

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

%E Definition corrected by _Harvey P. Dale_, Jul 25 2015

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)