login
This site is supported by donations 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
4, 6, 20, 25, 52, 59, 104, 119, 186, 211, 306, 338, 464, 502, 663, 715, 914, 981, 1222, 1297, 1585, 1667, 2004, 2104, 2494, 2615, 3062, 3191, 3700, 3854, 4429, 4610, 5256, 5466, 6186, 6426, 7224, 7477, 8356, 8620, 9582, 9878, 10929, 11261, 12405, 12774, 14014, 14422 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..48.

CROSSREFS

Sequence in context: A174936 A123169 A205955 * A024480 A066193 A026711

Adjacent sequences:  A023860 A023861 A023862 * A023864 A023865 A023866

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Title simplified by Sean A. Irvine, Jun 12 2019

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 November 21 22:40 EST 2019. Contains 329383 sequences. (Running on oeis4.)