login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268863 a(n)=least number m such that gcd(prime(m)+2,prime(m+1)+2) = 2*n-1. 2
1, 11, 61, 350, 180, 1010, 1933, 1006, 8555, 4154, 12089, 9696, 37932, 14173, 43447, 39464, 24706, 129178, 74854, 59257, 95206, 531300, 88480, 1280569, 934602, 818760, 85633, 232992, 2236506, 953991, 2768408, 2225450 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Zak Seidov, Table of n, a(n) for n = 1..50

EXAMPLE

n=1: m=1, p=prime(m)=2, q=prime(m+1)=3, gcd(p+2,q+2)=gcd(4,5)=1=2*1-1;

n=2: m=11, p=31, q=37, gcd(33,39)=3=2*2-1;

n=3: m=61, p=283, q=293, gcd(285, 295)=5=2*3-1;

n=50: m=15952683, p=294152659, q=294152857, gcd(294152661, 294152859)=99=2*50-1.

CROSSREFS

Sequence in context: A106992 A115565 A137410 * A199414 A156095 A068846

Adjacent sequences:  A268860 A268861 A268862 * A268864 A268865 A268866

KEYWORD

nonn

AUTHOR

Zak Seidov, Feb 15 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 7 16:00 EDT 2021. Contains 343652 sequences. (Running on oeis4.)