

A084563


Even numbers having no more than three partitions into two odd primes.


2



2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 38, 40, 44, 52, 56, 62, 68, 98, 128
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OFFSET

1,1


COMMENTS

A002375(a(n)/2) <= 3.
There are no other terms <= 30000. Could it be that no other terms exist?  John W. Layman, Jul 28 2003
There are no further terms < 100000.  Harvey P. Dale, Apr 17 2018


LINKS

Table of n, a(n) for n=1..25.
Eric Weisstein's World of Mathematics, Goldbach Partition.
Index entries for sequences related to Goldbach conjecture


MATHEMATICA

nn=10^2; ps=Boole[PrimeQ[Range[1, 2*nn, 2]]]; Select[Range[nn], Sum[ps[[i]]ps[[#i+1]], {i, Ceiling[#/2]}]<=3&]*2 (* Jayanta Basu, May 25 2013 *)
p2Q[n_]:=Count[nPrime[Range[2, PrimePi[n/2]]], _?PrimeQ]<4; Select[ 2*Range[70], p2Q] (* Harvey P. Dale, Apr 17 2018 *)


CROSSREFS

Cf. A084562, A084564.
Sequence in context: A084564 A053228 A141098 * A194396 A321193 A284788
Adjacent sequences: A084560 A084561 A084562 * A084564 A084565 A084566


KEYWORD

nonn,more


AUTHOR

Reinhard Zumkeller, May 30 2003


STATUS

approved



