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A111946 Triangle read by rows: T(n,k) = gcd(Fibonacci(n), Fibonacci(k)), 1 <= k <= n. 2
1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 5, 1, 1, 2, 1, 1, 8, 1, 1, 1, 1, 1, 1, 13, 1, 1, 1, 3, 1, 1, 1, 21, 1, 1, 2, 1, 1, 2, 1, 1, 34, 1, 1, 1, 1, 5, 1, 1, 1, 1, 55, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 89, 1, 1, 2, 3, 1, 8, 1, 3, 2, 1, 1, 144, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 233, 1, 1, 1, 1, 1, 1, 13, 1, 1, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,6

COMMENTS

The function T(n, k) is defined for all integers n, k but only the values for 1 <= k <= n as a triangular array are listed here.

REFERENCES

P. Ribenboim, FFF (Favorite Fibonacci Flowers), Fib. Q. 43 (No. 1, 2005), 3-14.

FORMULA

T(n, k) = Fibonacci(gcd(n, k)).

T(n, k) = T(k, n) = T(-n, k) = T(n, -k) = T(n, n+k) = T(n+k, k). [Michael Somos, Jul 18 2011]

EXAMPLE

{1}; {1,1}; {1,1,2}; {1,1,1,3}; {1,1,1,1,5}; {1,1,2,1,1,8}; ...

MATHEMATICA

T[ n_, k_] := Fibonacci @ GCD[ n, k] (* Michael Somos, Jul 18 2011 *)

PROG

(PARI) {T(n, k) = fibonacci( gcd( n, k))} /* Michael Somos, Jul 18 2011 */

CROSSREFS

Cf. A000045, A111956, A111957.

Sequence in context: A085476 A124944 A094392 * A175788 A137844 A079229

Adjacent sequences:  A111943 A111944 A111945 * A111947 A111948 A111949

KEYWORD

nonn,tabl

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Nov 28 2005

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.