A038609 Numbers that are the sum of 2 different primes.

5, 7, 8, 9, 10, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 24, 25, 26, 28, 30, 31, 32, 33, 34, 36, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 50, 52, 54, 55, 56, 58, 60, 61, 62, 63, 64, 66, 68, 69, 70, 72, 73, 74, 75, 76, 78, 80, 81, 82, 84, 85, 86, 88, 90, 91, 92

Offset: 1

Author

Vasiliy Danilov (danilovv(AT)usa.net) 1998 Jul

Keywords

• nonn

Links

• R. J. Mathar, Table of n, a(n) for n = 1..9225

Crossrefs

Cf. A014091, A166081 (complement).

Programs

Maple

isA038609 := proc(n)
    local i,p,q;
    for i from 1 do
        p := ithprime(i) ;
        if 2*p > n then
            return false;
        fi;
        q := n-p ;
        if q <= p then
            return false ;
        end if;
        if isprime(q) then
            return true;
        end if;
    end do:
end proc:
n :=1 :
for c from 1 do
    if isA038609(c) then
        printf("%d %d\n",n,c) ;
        n := n+1 ;
    end if;
end do: # R. J. Mathar, Jun 09 2014

Mathematica

max = 100;
ip = PrimePi[max];
Table[Prime[i] + Prime[j], {i, ip}, {j, i + 1, ip}] // Flatten // Union // Select[#, # <= max&]& (* Jean-François Alcover, Mar 23 2020 *)