[seqfan] On some constellatijns of primes

юрий герасимов 2stepan at rambler.ru
Thu Oct 18 17:13:14 CEST 2012



Dear SegFans, 
If 1^0 + 2^1/2 = 1 + 1 = 2  is prime for n = 0; 
1^2 + 2^3/2 = 1 + 4 = 5  is prime for n = 1; 
3^2 + 4^3/2 = 9 + 32 = 41  is prime for n = 2; 
3^4 + 4^5/2 = 81 + 512 = 593  is prime for n = 3; 
5^4 + 6^5/2 = 625 + 3888 = 4513  is prime for n = 4; 
5^6 + 6^7/2 = 15625 + 139968 = 155593  is prime for n = 5,...
i. e.  a(n) = (n + (1 + (-1)^n)/2)^(n + (1 + (-1)^(n + 1))/2) + (n + 1 + (1 + (-1)^n)/2)^(n + 1 + (1 + (-1)^(n + 1))/2)/2 (I can't find the sequence in the OEIS), 
then primes of the form (n + (1 + (-1)^n)/2)^(n + (1 + (-1)^(n + 1))/2) + (n + 1 + (1 + (-1)^n)/2)^(n + 1 + (1 + (-1)^(n + 1))/2)/2 (I can't find the sequence in the OEIS) are a(0) = 2, a(1) = 5, a(2) = 41, a(3) = 593, a(4) = 4513, a(5) = 155593, a(6) = ?, a(7) = ?, a(8) = ?. 
Regards, 
JSG



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