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!)
A073900 a(1) = 1; then k-th prime prime(k) followed by Floor[e^k] consecutive composite numbers not occurring earlier. 1

%I #4 Dec 05 2013 19:55:32

%S 1,2,4,6,3,8,9,10,12,14,15,16,5,18,20,21,22,24,25,26,27,28,30,32,33,

%T 34,35,36,38,39,40,42,44,7,45,46,48,49,50,51,52,54,55,56,57,58,60,62,

%U 63,64,65,66,68,69,70,72,74,75,76,77,78,80,81,82,84,85,86,87,88,90,91,92

%N a(1) = 1; then k-th prime prime(k) followed by Floor[e^k] consecutive composite numbers not occurring earlier.

%C Primes grow faster than composites. Question: For what (the smallest) value of m a(m) is prime and more than the previous term which is obviously composite.?

%e a(2) =2 and Floor[e] = 2 hence a(3) and a(4) are 4 and 6 respectively. a(5) = 3 (the second prime) and Floor[e^2]=7, hence next 7 terms are 8,9,10,12,14,15 and 16.

%Y Cf. A073899.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Aug 18 2002

%E Edited by _T. D. Noe_, Apr 13 2009

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 July 24 14:22 EDT 2024. Contains 374584 sequences. (Running on oeis4.)