cp's OEIS Frontend

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.

%I A082867 #17 Jul 05 2022 12:24:17
%S A082867 8,15,20,24,27,32,35,39,44,48,51,56,65,68,75,80,84,87,90,92,95,99,104,
%T A082867 111,116,119,120,125,128,132,135,140,143,144,147,152,155,159,164,168,
%U A082867 171,175,176,185,188,189,195,200,204,207,212,216,219,224,231,236,245
%N 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.
%H A082867 Amiram Eldar, <a href="/A082867/b082867.txt">Table of n, a(n) for n = 1..10000</a>
%e A082867 8 is a member because 2 divides 8, 3 divides 9 (and 4 does not divide 10).
%o A082867 (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 A082867 Cf. A082772.
%K A082867 easy,nonn
%O A082867 1,1
%A A082867 Anne M. Donovan (anned3005(AT)aol.com), May 24 2003
%E A082867 Corrected by _T. D. Noe_, Oct 25 2006