A079506 Numbers k with gcd(2^k-1, Fibonacci(k)) > 1 and not divisible by 2 or 11. Odd members of A074776 not divisible by 11.

261, 305, 333, 377, 525, 651, 753, 783, 895, 915, 999, 1131, 1305, 1475, 1525, 1575, 1665, 1827, 1885, 1953, 2135, 2235, 2259, 2265, 2283, 2319, 2331, 2349, 2515, 2601, 2625, 2639, 2685, 2743, 2745, 2867, 2921, 2975, 2997, 3255, 3393, 3549, 3675, 3765

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

Example: gcd(2^261-1, Fibonacci(261)) = 2089 and 11 does not divide 261, so 261 is in the sequence.

Mathematica

Select[2*Range[2000]-1, !Divisible[#, 11] && !CoprimeQ[2^# - 1, Fibonacci[#]] &] (* Amiram Eldar, May 14 2022 *)

Prog

(PARI) for(k=1, 5000, if(gcd(2^k-1, fibonacci(k))>1, if(k%2, if(k%11, print1(k", ")))))

Crossrefs

Cf. A000045, A000225, A074776.

Sequence in context: A345559 A345814 A131062 * A028527 A014569 A063364

Adjacent sequences: A079503 A079504 A079505 * A079507 A079508 A079509

Keyword

nonn

Author

Ralf Stephan, Jan 21 2003

Status

approved