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!)
A082867 Numbers n such that there exists a proper divisor 1 < m < n where m divides n and m+1 divides n+1, but there is no divisor d such that d divides n, d+1 divides n+1 and d+2 divides n+2. 2

%I #17 Jul 05 2022 12:24:17

%S 8,15,20,24,27,32,35,39,44,48,51,56,65,68,75,80,84,87,90,92,95,99,104,

%T 111,116,119,120,125,128,132,135,140,143,144,147,152,155,159,164,168,

%U 171,175,176,185,188,189,195,200,204,207,212,216,219,224,231,236,245

%N Numbers n such that there exists a proper divisor 1 < m < n where m divides n and m+1 divides n+1, but there is no divisor d such that d divides n, d+1 divides n+1 and d+2 divides n+2.

%H Amiram Eldar, <a href="/A082867/b082867.txt">Table of n, a(n) for n = 1..10000</a>

%e 8 is a member because 2 divides 8, 3 divides 9 (and 4 does not divide 10).

%o (PARI) is(n)=my(t); fordiv(n,m, if(m==1, next); if((n+1)%(m+1)==0, if(m==n, return(t)); t=1; if((n+2)%(m+2)==0, return(0)))) \\ _Charles R Greathouse IV_, Jul 05 2022

%Y Cf. A082772.

%K easy,nonn

%O 1,1

%A Anne M. Donovan (anned3005(AT)aol.com), May 24 2003

%E Corrected by _T. D. Noe_, Oct 25 2006

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 August 28 12:00 EDT 2024. Contains 375507 sequences. (Running on oeis4.)