[seqfan] A219923

[юрий герасимов]

Dear SegFans, 
If 
A219923  Number of ways to write n = x + y (x > 0, y > 0) with x - 1, x + 1 and 2*x*y + 1 all prime:  0, 0, 0, 0, ...
these 
A______? Number of ways to write 2*n + 1 = x + y with (x + 1)*2^(y - 1) + (y + 1)*2^(x - 1) prime: 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ..a(n >22) = (1 or 2) ?
because 
a(0) = (0 + 1)*2^(1 - 1) + (1 + 1)*2^(0 - 1) = 1*2^0 + 2*2^(-1) = 1 + 1 = 2 prime; 
a(1) = (1 + 1)*2^(2 - 1) + (2 + 1)*2^(1 - 1) = 2*2^1 + 3*2^0 = 4 + 3 = 7 prime; 
a(2) = (0 + 1)*2^(5 - 1) + (5 + 1)*2^(0 - 1) = 1*2^4 + 6*2*(-1) = 16 + 3 = 19 prime; 
a(3) = (1 + 1)*2^(6 - 1) + (6 + 1)*2^(1 - 1) = 2*2^5 + 7*2^0 = 64 + 7 = 71 prime,...
or 
A           ? Primes of the form (x + 1)*2^(y - 1) + (y + 1)*2^(x - 1) : 2, 7, 19, 71, a(4) = ?, a(5) = ?, a(6) = ?
Regards, 
Juri-Stepan Gerasimov.