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!)
A157892 Values of k in A080075. 3

%I #8 Nov 05 2019 00:59:25

%S 1,1,1,3,1,3,1,5,3,7,1,5,3,7,1,9,5,11,3,13,7,15,1,9,5,11,3,13,7,15,1,

%T 17,9,19,5,21,11,23,3,25,13,27,7,29,15,31,1,17,9,19,5,21,11,23,3,25,

%U 13,27,7,29,15,31,1,33,17,35,9,37,19,39,5,41,21,43,11,45,23,47,3,49,25,51,13

%N Values of k in A080075.

%H Michael De Vlieger, <a href="/A157892/b157892.txt">Table of n, a(n) for n = 1..10000</a>

%H Zak Seidov, <a href="http://zak08.livejournal.com/5727.html">A157892</a>

%H Amelia Carolina Sparavigna, <a href="https://doi.org/10.5281/zenodo.3339313">Discussion of the groupoid of Proth numbers (OEIS A080075)</a>, Politecnico di Torino, Italy (2019).

%t Select[Table[Append[QuotientRemainder[#1, 2^#2], #2] & @@ {#, IntegerExponent[#, 2]} &[n - 1], {n, 3, 3360, 2}], And[OddQ[#[[1]] ], #[[-1]] >= 1, 2^#[[-1]] > #[[1]] ] &][[All, 1]] (* _Michael De Vlieger_, Nov 04 2019 *)

%Y Cf. A157893 (Values of m in A080075).

%Y Cf. A080075 (Proth numbers : of the form k*2^m + 1 for k odd, m >= 1 and 2^m > k).

%K nonn

%O 1,4

%A _Zak Seidov_, Mar 08 2009

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 March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)