1,1

n=31877 yields a probable prime; the others have been proved prime. These n were also found by Eric Weisstein, who found no other n<100000.

Eric Weisstein's World of Mathematics, Central Trinomial Coefficient

Eric Weisstein's World of Mathematics, Integer Sequence Primes

Select[Range[200], PrimeQ[Coefficient[Expand[(x^2-x-1)^# ], x, # ]]&]

Cf. A098331 (coefficient of x^n in (x^2-x-1)^n).

Adjacent sequences: A112871 A112872 A112873 this_sequence A112875 A112876 A112877

Sequence in context: A022555 A047308 A092860 this_sequence A106155 A087190 A085038

hard,nonn

T. D. Noe (noe(AT)sspectra.com), Sep 29 2005