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

1,1

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

Cf. A034961, A141468.

Sequence in context: A314257 A314258 A314259 * A314260 A314261 A314262

Adjacent sequences: A166036 A166037 A166038 * A166040 A166041 A166042

Keyword

nonn

Author

Juri-Stepan Gerasimov, Oct 05 2009

Status

approved