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Revision History for A263468

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Fibonacci primes equal to a sum of squares of two Fibonacci numbers at least one of which is also prime.
(history; published version)
#10 by Bruno Berselli at Thu Nov 05 08:16:53 EST 2015
STATUS

proposed

approved

#9 by Jonathan Sondow at Thu Nov 05 07:50:07 EST 2015
STATUS

editing

proposed

#8 by Jonathan Sondow at Thu Nov 05 07:50:03 EST 2015
COMMENTS

Same as Fibonacci numbers F(2k+1) such that at least two of the numbers F(2k+1), F(k), F(k+1) are prime (because F(2k+1) = F(k)^2 + F(k+1)^2 for any kand F(a*b)= F(a) * F(b))). Thus the two squares are of consecutive Fibonacci numbers.

STATUS

proposed

editing

#7 by Jonathan Sondow at Thu Nov 05 07:44:51 EST 2015
STATUS

editing

proposed

#6 by Jonathan Sondow at Thu Nov 05 07:44:16 EST 2015
COMMENTS

Same as Fibonacci numbers F(2k+1) such that at least two of the numbers F(2k+1), F(k), F(k+1) are prime (because F(2k+1) = F(k)^2 + F(k+1)^2 for any k). Thus the two squares are of consecutive Fibonacci numbers.

No other terms up to FibonacciF(2904353).

Subsequence of A002144 and A002313.

EXAMPLE

FibonacciF(47) = 2971215073 = 28657^2 + 46368^2 = FibonacciF(23)^2 + FibonacciF(24)^2 and 2971215073 and 28657 are prime, so 2971215073 is a member.

KEYWORD

nonn,more,new

STATUS

approved

editing

#5 by Michael Somos at Wed Nov 04 22:25:10 EST 2015
STATUS

proposed

approved

#4 by Jonathan Sondow at Wed Nov 04 21:20:10 EST 2015
STATUS

editing

proposed

#3 by Jonathan Sondow at Wed Nov 04 21:20:03 EST 2015
COMMENTS

Same as Fibonacci numbers F(2k+1) such that at least two of the numbers F(2k+1), F(k), F(k+1) are prime (because F(2k+1) = F(k)^2 + F(k+1)^2 for any k).

EXAMPLE

Fibonacci(47) = 2971215073 = 28657^2 + 46368^2 = Fibonacci(23)^2 + Fibonacci(24)^2 and 2971215073 and 28657 are prime, so 2971215073 is a member.

#2 by Jonathan Sondow at Wed Nov 04 21:13:24 EST 2015
NAME

allocated for Jonathan SondowFibonacci primes equal to a sum of squares of two Fibonacci numbers at least one of which is also prime.

DATA

5, 13, 89, 233, 28657, 2971215073

OFFSET

1,1

COMMENTS

No other terms up to Fibonacci(2904353).

The corresponding Fibonacci indices are in A263467.

LINKS

Wikipedia, <a href="https://en.wikipedia.org/wiki/Fibonacci_number">Fibonacci number</a>

Wikipedia, <a href="https://en.wikipedia.org/wiki/Fibonacci_prime">Fibonacci prime</a>

FORMULA

a(n) = A000045(A263467(n)).

EXAMPLE

Fibonacci(47) = 2971215073 = 28657^2 + 46368^2 = Fibonacci(23)^2 + Fibonacci(24)^2 and 2971215073 and 28657 are prime, so 2971215073 is a member.

CROSSREFS
KEYWORD

allocated

nonn

AUTHOR

Jonathan Sondow, Nov 04 2015

STATUS

approved

editing

#1 by Jonathan Sondow at Mon Oct 19 11:57:13 EDT 2015
NAME

allocated for Jonathan Sondow

KEYWORD

allocated

STATUS

approved