A114419 - OEIS

A114419

a(n) is the smallest number k such that Fibonacci(k) is a multiple of primorial(n).

3, 12, 60, 120, 120, 840, 2520, 2520, 2520, 2520, 2520, 47880, 47880, 526680, 1053360, 3160080, 91642320, 91642320, 1557919440, 1557919440, 57643019280, 749359250640, 749359250640, 749359250640, 5245514754480, 26227573772400

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OFFSET

1,1

COMMENTS

Because the Fibonacci numbers form a divisibility sequence, each term of this sequence is a multiple of the previous term. The multiple can be computed using A001602. - T. D. Noe, May 04 2009

LINKS

Zak Seidov, Table of n, a(n) for n = 1..100

Index to divisibility sequences

FORMULA

a(n) = {min j: A002110(n) | A000045(j)}. - R. J. Mathar, Jan 31 2008

a(n) = lcm(A001602(1),...,A001602(n)). - T. D. Noe, May 04 2009

EXAMPLE

a(2)=12 because 12th Fibonacci number (144) is the smallest Fibonacci number which is a multiple of primorial(2), i.e., 6.

PROG

(PARI) a(n) = {prn = prod(k=1, n, prime(k)); k = 1; while(fibonacci(k) % prn, k++); k; } \\ Michel Marcus, Jan 13 2016

CROSSREFS

Cf. A002110, A000045.