Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
a(n) is the least i such that Fibonacci(i) is divisible by i+k for all k=0..n.
1

%I #19 May 18 2018 20:03:16

%S 1,60,60,540,13440,13440,329400,175472640,50238568800

%N a(n) is the least i such that Fibonacci(i) is divisible by i+k for all k=0..n.

%C a(0)..a(5) are first terms of sequences A023172, A217738, A298684, A298685, A298686, A298687.

%e Least i such that Fibonacci(i) is divisible by i and i+1 (cf. A217738) is i=60, therefore a(1)=60.

%e Least i such that Fibonacci(i) is divisible by i, i+1, ..., i+5 (cf. A298687) is i=13440, therefore a(5)=13440.

%Y Cf. A000045, A023172, A217738, A221018, A225219, A298684, A298685, A298686, A298687.

%K nonn,hard,more

%O 0,2

%A _Alex Ratushnyak_, Jan 24 2018

%E a(7) from _Alois P. Heinz_, Jan 25 2018

%E a(6) inserted by _Chai Wah Wu_, Jan 26 2018

%E a(8) from _Silvester Resnik_, May 18 2018