A274584 Composite numbers n such that primitive part of Fibonacci(n) is prime.

4, 8, 9, 10, 14, 15, 16, 18, 20, 21, 22, 26, 28, 30, 32, 33, 34, 35, 38, 39, 40, 42, 45, 51, 52, 54, 60, 62, 63, 65, 66, 72, 74, 75, 76, 82, 93, 94, 98, 105, 106, 111, 112, 119, 121, 122, 123, 124, 132, 135, 136, 140, 142, 144, 145, 152, 156, 158, 160, 172, 180

Offset: 1

Author

Arkadiusz Wesolowski, Jun 29 2016

Keywords

• nonn

Comments

For every n > 1, A105602(a(n)) > 1.

Links

• Arkadiusz Wesolowski, Table of n, a(n) for n = 1..350
• C. K. Caldwell, Top Twenty page, Fibonacci Primitive Part

Crossrefs

Cf. A061446. Supersequence of A061254.

Programs

Magma

lst:=[]; for n in [4..180] do if not IsPrime(n) then d:=Divisors(n); p:=Truncate(&*[Fibonacci(d[i])^MoebiusMu(Truncate(n/d[i])): i in [1..#d]]); if IsPrime(p) then Append(~lst, n); end if; end if; end for; lst;