A152013 Indices of Fibonacci numbers having at least two distinct primitive prime factors.

19, 27, 31, 37, 41, 44, 46, 49, 50, 53, 55, 57, 58, 59, 61, 64, 67, 68, 69, 70, 71, 73, 77, 78, 79, 80, 81, 84, 85, 86, 87, 88, 89, 90, 91, 92, 95, 96, 97, 99, 100, 101, 102, 103, 104, 107, 109, 110, 113, 114, 115, 116, 117, 118, 120, 126, 127, 128, 129, 130, 133, 134

Offset: 1

Author

Max Alekseyev, Nov 19 2008

Keywords

• nonn

Comments

It is known that Fibonacci number A000045(n) has a primitive prime factor for all n, except n=0, 1, 2, 6 and 12. This sequence lists such indices n that A000045(n) has at least two primitive prime factors. Its sister sequence A152012 provides indices of Fibonacci numbers with exactly one primitive prime factor. The current sequence A152013 and its sister sequence A152012 along with the finite set {0,1,2,6,12} form a partition of the natural numbers.

Crossrefs

Cf. A000045, A001578, A152012.