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!)
A023863 a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A002808 (composite numbers). 0

%I #7 Jun 12 2019 19:15:53

%S 4,6,20,25,52,59,104,119,186,211,306,338,464,502,663,715,914,981,1222,

%T 1297,1585,1667,2004,2104,2494,2615,3062,3191,3700,3854,4429,4610,

%U 5256,5466,6186,6426,7224,7477,8356,8620,9582,9878,10929,11261,12405,12774,14014,14422

%N a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A002808 (composite numbers).

%K nonn

%O 1,1

%A _Clark Kimberling_

%E Title simplified by _Sean A. Irvine_, Jun 12 2019

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 April 25 12:33 EDT 2024. Contains 371969 sequences. (Running on oeis4.)