1,1

3/2 + (-1)^n/2 adds 1 for any even number and 2 for any odd number

5 is a member because 2^2+3/2-1/2=5

P:=proc(n) local i, j; for i from 0 by 1 to n do j:=i^2+3/2-1/2*(-1)^i; if isprime(j) then print(j); fi; od; end: P(200);

Sequence in context: A006171 A060647 A155989 this_sequence A007455 A034729 A115786

Adjacent sequences: A125554 A125555 A125556 this_sequence A125558 A125559 A125560

easy,nonn

Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Dec 31 2006