A166039 Sums of three consecutive nonprimes A141468.

5, 11, 18, 23, 27, 31, 36, 41, 45, 49, 54, 59, 63, 67, 71, 75, 78, 81, 85, 90, 95, 99, 102, 105, 109, 113, 117, 121, 126, 131, 135, 139, 143, 147, 150, 153, 157, 161, 165, 168, 171, 175, 180, 185, 189, 192, 195, 199, 203, 207, 211, 216, 221, 225, 228, 231, 235

Offset: 1

Author

Juri-Stepan Gerasimov, Oct 05 2009

Keywords

• nonn

Examples

			a(1) = 0 + 1 + 4 =  5;
a(2) = 1 + 4 + 6 = 11;
a(3) = 4 + 6 + 8 = 18.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A034961, A141468.

Programs

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 *)