A084563 Even numbers having no more than three partitions into two odd primes.

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

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[n-Prime[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: A053228 A368861 A141098 * A194396 A321193 A284788

Adjacent sequences: A084560 A084561 A084562 * A084564 A084565 A084566

Keyword

nonn,more

Author

Reinhard Zumkeller, May 30 2003

Status

approved