A141098 Even numbers not representable as the sum of two coprime composite numbers.

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 36, 38, 40, 42, 48, 50, 54, 56, 60, 66, 70, 72, 78, 80, 84, 90, 96, 108, 110, 120, 126, 132, 138, 140, 150, 180, 210

Offset

1,1

Comments

210 is the last term.

Links

Table of n, a(n) for n=1..43.

Mathematica

t = Table[Length[Select[Range[2, n/2], ! PrimeQ[#] && ! PrimeQ[n - #] && GCD[#, n - #] == 1 &]], {n, 2, 2000, 2}]; Flatten[2*Position[t, 0]] (* T. D. Noe, Dec 05 2013 *)

Crossrefs

This sequence is a superset of A141096. See A141097.

Sequence in context: A084564 A053228 A368861 * A084563 A194396 A321193

Adjacent sequences: A141095 A141096 A141097 * A141099 A141100 A141101

Keyword

nonn,fini,full

Author

T. D. Noe, Jun 02 2008

Status

approved