A137574 Fibonacci numbers and their distinct prime divisors having the same number of decimal digits.

2, 3, 5, 8, 13, 21, 89, 233, 1597, 17711, 28657, 46368, 75025, 121393, 514229, 1346269, 165580141, 433494437, 2971215073, 53316291173, 139583862445, 2504730781961, 308061521170129, 806515533049393, 14472334024676221, 99194853094755497, 19740274219868223167

Offset: 1

Author

Parthasarathy Nambi, Apr 25 2008

Keywords

• nonn
• base

Comments

The Fibonacci primes are part of this sequence.

Fibonacci numbers which are semiprimes are also part of the sequence.

Examples

			The Fibonacci number 53316291173 and its prime divisors 953 and 55945741 have exactly the same number of decimal digits.
		

Links

• Ron Knott, Fibonacci Numbers and their prime divisors.

Crossrefs

Cf. A000045, A053409.

Programs

Mathematica

Select[Fibonacci[Range[3,100]],IntegerLength[#]==Total[IntegerLength/@First/@FactorInteger[#]]&] (* James C. McMahon, May 30 2025 *)

Extensions

a(21)-a(27) from James C. McMahon, May 30 2025