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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A115061 a(n) is the number of occurrences of the n-th prime number in A051697. 3

%I

%S 3,2,2,3,3,3,3,3,5,4,4,5,3,3,5,6,4,4,5,3,4,5,5,7,6,3,3,3,3,9,9,5,4,6,

%T 6,4,6,5,5,6,4,6,6,3,3,7,12,8,3,3,5,4,6,8,6,6,4,4,5,3,6,12,9,3,3,9,10,

%U 8,6,3,5,7,7,6,5,5,7,6,6

%N a(n) is the number of occurrences of the n-th prime number in A051697.

%C Except for the second entry, the sequence also holds with respect to A077018.

%C a(n) equals A162345(n) for n>1 and equals A052288(n-2) for n>2. - _Nathaniel Johnston_, Jun 25 2011

%H Nathaniel Johnston, <a href="/A115061/b115061.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = (prime(n+1) - prime(n-1))/2 for n>=3. - _Nathaniel Johnston_, Jun 25 2011

%e The 5th prime number, 11, appears three times in A051697. Therefore a(5) = 3.

%t a = {3}; For[n = 2, n < 100, n++, c = 0; For[j = Prime[n - 1], j < Prime[n + 1], j++, If[j < Prime[n], If[Prime[n] - j < j - Prime[n - 1], c++ ], If[Not[Prime[n + 1] - j < j - Prime[n]], c++ ]]]; AppendTo[a, c]]; a

%K nonn,easy

%O 1,1

%A _Lekraj Beedassy_, Mar 01 2006

%E Edited and extended by _Stefan Steinerberger_, Oct 27 2007

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 January 19 14:53 EST 2020. Contains 331049 sequences. (Running on oeis4.)