OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
EXAMPLE
a(1) = 0 + 1 + 4 = 5;
a(2) = 1 + 4 + 6 = 11;
a(3) = 4 + 6 + 8 = 18.
MAPLE
A002808 := proc(n) option remember; if n = 1 then 4; else for a from procname(n-1)+1 do if not isprime(a) then return a; fi; od: fi; end: A141468 := proc(n) if n <= 2 then n-1 ; else A002808(n-2) ; fi; end: A166039 := proc(n) add(A141468(j), j=n..n+2) ; end: seq(A166039(n), n=1..120) ; # R. J. Mathar, Oct 10 2009
MATHEMATICA
With[{nn=100}, Total/@Partition[Complement[Range[0, nn], Prime[ Range[ PrimePi[ nn]]]], 3, 1]] (* Harvey P. Dale, Aug 05 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Oct 05 2009
STATUS
approved