A270839 Integers k such that (A003266(k)/A000045(k-1)) is not divisible by k.

2, 3, 4, 7, 9, 11, 19, 23, 31, 43, 59, 67, 71, 79, 83, 103, 127, 131, 163, 167, 179, 191, 223, 227, 239, 251, 271, 283, 311, 359, 367, 379, 383, 419, 431, 439, 443, 463, 467, 479, 487, 491, 499, 503, 523, 547, 571, 587, 599, 607, 631, 643, 647, 659, 683, 719, 727, 739, 751, 787, 823, 827, 839

Offset: 1

Author

Altug Alkan, Mar 23 2016

Keywords

• nonn

Comments

A270777 is a subsequence.

It appears that this sequence generates prime numbers except 4 and 9. [Verified for the first 500 terms. - Amiram Eldar, Apr 01 2021]

Examples

			3 is a term because 1*2 is not divisible by 3.
7 is a term because 1*1*2*3*5*13 is not divisible by 7.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A000045, A000057, A003266, A270777.

Programs

Mathematica

Select[Range[2, 840], ! Divisible[Fibonorial@ #/Fibonacci[# - 1], #] &] (* Version 10, or *) Select[Range[2, 840], ! Divisible[Product[Fibonacci@ k, {k, #}]/Fibonacci[# - 1], #] &] (* Michael De Vlieger, Mar 24 2016 *)

PARI

t(n) = fibonacci(n) * prod(k=1, n-2, Mod(fibonacci(k), n));
for(n=2, 1e3, if(lift(t(n)) != 0, print1(n, ", ")));

Extensions

Offset corrected by Amiram Eldar, Apr 01 2021