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!)
A080373 a(n) is the smallest number such that GCD of n values of prime(j)-1 for successive j values is greater than 2, where prime(j)=j-th prime. 0

%I

%S 0,6,24,77,271,271,1395,1395,1395,13717,34369,172146,172146,804584,

%T 804584,804584

%N a(n) is the smallest number such that GCD of n values of prime(j)-1 for successive j values is greater than 2, where prime(j)=j-th prime.

%F a(n) = Min{x; gcd[prime(x)-1, ..., prime(x+n-1)]>2}, where prime()=A000040().

%e n=2: a(2)=6=A067605(2);

%e n=3: a(3)=24 means: firstly occurs that for three consecutive p-1 terms GCD[prime(24)-1, prime(25)-1, prime(26)-1] = GCD[88, 96, 100] = 4 > 2;

%Y Cf. A058263, A067605.

%K nonn,more

%O 1,2

%A _Labos Elemer_, Feb 26 2003

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 11 22:58 EDT 2022. Contains 356067 sequences. (Running on oeis4.)