The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A075339 a(1) = 1, a(2n) = smallest composite number obtained by adding a prime to a(2n-1). a(2n+1) = the smallest prime obtained by adding a composite number to a(2n). 0

%I #4 Dec 05 2013 19:55:37

%S 1,4,13,15,19,21,29,32,41,44,53,55,59,62,71,74,83,85,89,91,97,99,103,

%T 105,109,111,127,129,137,140,149,152,167,169,173,175,179,182,191,194,

%U 227,230,239,242,251,253,257,259,263,265,269,272,281,284,293,295,307

%N a(1) = 1, a(2n) = smallest composite number obtained by adding a prime to a(2n-1). a(2n+1) = the smallest prime obtained by adding a composite number to a(2n).

%C a(k) = b(k-1) for k > 6 where b(r) is the r-th term of A075338.

%Y Cf. A075338.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Sep 18 2002

%E More terms from _David Wasserman_, Jan 16 2005

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.

Last modified June 2 10:25 EDT 2023. Contains 363097 sequences. (Running on oeis4.)