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

1,1

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]

Links

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

Example

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.

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 *)

Prog

(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, ", ")));

Crossrefs

Cf. A000045, A000057, A003266, A270777.

Sequence in context: A236337 A191989 A084913 * A117450 A132381 A073152

Adjacent sequences: A270836 A270837 A270838 * A270840 A270841 A270842

Keyword

nonn

Author

Altug Alkan, Mar 23 2016

Extensions

Offset corrected by Amiram Eldar, Apr 01 2021

Status

approved