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+--- Thread: (38G) Fibonacci Numbers (/thread-3564.html)
(38G) Fibonacci Numbers - Gerald H - 04-06-2015 11:19 AM
Two programmes:
FIBO takes non-negative integer input N & returns the Nth Fibonacci number in Ans, exact for N < 60.
FIBO
ROUND(((1+√5)/2)^Ans/√5,0)-(Ans>55)-(Ans>57)*2-(Ans>58)*2:
FIBO? takes non-negative integer input N & returns 1 if N is a Fibonacci number, else 0, correct for N < 447214.
FIBO?
5*Ans^2+4:
IFTE(FRAC(√Ans),IFTE(FRAC(√(Ans-8)),0,1),1):
RE: HP 38G: Fibonacci Numbers - Gerald H - 04-28-2015 05:52 AM
You can put the formula in the Sequence Aplet using the programme FIBOSEQ.
U2 gives the partial sums of the Fibonacci series.
FIBOSEQ
RUN SEQSET:
RECURSE(U,ROUND(((1+√5)/2)^N/√5,0)-(N>55)-(N>57)*2-(N>58)*2,1,1)►U1(N):
CHECK 1:
RECURSE(U,U1(N+2)-1,1,2)►U2(N):
CHECK 2: