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A231903 Even numbers which are the sum of two different primes > 3 in exactly one way. 0

%I

%S 12,16,20,22,26,32,38,62

%N Even numbers which are the sum of two different primes > 3 in exactly one way.

%C Conjecture: there are no more numbers > 62 in the sequence.

%C Remark that the two primes are one of a twin primes pair and a pair of twin primes for 12=5+7.

%C The pairs of primes are : 12=5+7, 16=5+11, 20=7+13, 22=5+17, 26=7+19, 32=13+19, 38=7+31, 62=19+43.

%e 10=3+7=5+5 not in the sequence (not >3 or not different),

%e 12=5+7, 12 first in the sequence,

%e 14=3+11=7+7 not in the sequence.

%o (PARI) is_A231903(n)={my(s=0);forprime(p=5,n\2-1,isprime(n-p)&&s++>1&&return);s} \\ - _M. F. Hasler_, Nov 22 2013

%Y Cf. A007534

%K nonn

%O 1,1

%A _Pierre CAMI_, Nov 15 2013

%E Missing term a(7)=38 added by _M. F. Hasler_, Nov 22 2013

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Last modified January 22 12:12 EST 2022. Contains 350481 sequences. (Running on oeis4.)