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!)
A078832 Smallest prime contained as binary substring in binary representation of n>1, a(1)=1. 3

%I #7 Jul 17 2015 05:58:18

%S 1,2,3,2,2,2,3,2,2,2,2,2,2,2,3,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,2,2,2,

%T 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,2,2,2,2,2,

%U 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2

%N Smallest prime contained as binary substring in binary representation of n>1, a(1)=1.

%C a(n)<=3 and for n>1: a(n)>=2 and a(n)=3 iff n=2^k-1, k>1.

%C a(n) = A225243(n,1). - _Reinhard Zumkeller_, Aug 14 2013

%H Reinhard Zumkeller, <a href="/A078832/b078832.txt">Table of n, a(n) for n = 1..10000</a>

%F For n > 1: a(n) = A036987(n) + 2. _Reinhard Zumkeller_, Aug 14 2013

%o (Haskell)

%o a078832 = head . a225243_row -- _Reinhard Zumkeller_, Aug 14 2013

%Y Cf. A078833, A078826, A078822, A007088, A020639.

%Y Cf. A030308, A010051, A000225.

%K nonn,base

%O 1,2

%A _Reinhard Zumkeller_, Dec 08 2002

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 May 11 23:16 EDT 2024. Contains 372431 sequences. (Running on oeis4.)