login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

List of numbers whose middle Fibonomial coefficient (2n,n)_F is prime to 105.
0

%I #16 Jan 05 2025 19:51:41

%S 1,1312,3256,3257,3936,3937,4000,4001,4032,38880,38881,39000,39001,

%T 19928280,19928281,21975136,21975137,21975305,21975312,22054032

%N List of numbers whose middle Fibonomial coefficient (2n,n)_F is prime to 105.

%C From _Charlie Neder_, Mar 04 2019: (Start)

%C For the middle Fibonomial coefficient (2n,n)_F to be coprime to a prime p, we must have that the integral part of n/A001177(p) has its base-p digits all < p/2 and its fractional part is < 1/2.

%C Next term > 10^8. (End)

%H Christian Ballot, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Papers1/55-4/BallotLucasCatalan101717.pdf">Divisibility of the middle Lucasnomial coefficient</a>, Fib. Q., 55 (2017), 297-308.

%F Numbers k congruent to 0 or 1 modulo 8 such that floor(k/4) is in A005836, k is in A037543, and floor(k/8) is in A037461. - _Charlie Neder_, Mar 04 2019

%Y Cf. A003267, A030979.

%Y Cf. A037461, A037543, A005836.

%K nonn,more,changed

%O 1,2

%A _N. J. A. Sloane_, Nov 28 2017

%E a(10)-a(20) from _Charlie Neder_, Mar 04 2019