A121568 Fibonacci[ (p - 1)/2 ], where p = Prime[n].

1, 1, 2, 5, 8, 21, 34, 89, 377, 610, 2584, 6765, 10946, 28657, 121393, 514229, 832040, 3524578, 9227465, 14930352, 63245986, 165580141, 701408733, 4807526976, 12586269025, 20365011074, 53316291173, 86267571272, 225851433717

Offset: 2

Author

Alexander Adamchuk, Aug 07 2006

Keywords

• nonn

Comments

p = Prime[n] divides a(n) = Fibonacci[(p-1)/2] for p = {29,41,61,89,101,109,149,181,229,241,269,281,349,381,...} = A033205[n] Primes of form x^2+5*y^2 excluding A033205[1] = 5.

Crossrefs

Cf. A000045, A121567, A033205, A045468, A064739.

Programs

Mathematica

Table[Fibonacci[(Prime[n]-1)/2],{n,2,50}]

Formula

a(n) = Fibonacci[ (Prime[n]-1)/2 ], n>1.