This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A137574 #7 May 31 2025 11:09:11 %S A137574 2,3,5,8,13,21,89,233,1597,17711,28657,46368,75025,121393,514229, %T A137574 1346269,165580141,433494437,2971215073,53316291173,139583862445, %U A137574 2504730781961,308061521170129,806515533049393,14472334024676221,99194853094755497,19740274219868223167 %N A137574 Fibonacci numbers and their distinct prime divisors having the same number of decimal digits. %C A137574 The Fibonacci primes are part of this sequence. %C A137574 Fibonacci numbers which are semiprimes are also part of the sequence. %H A137574 Ron Knott, <a href="http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fibtable.html#100">Fibonacci Numbers and their prime divisors</a>. %e A137574 The Fibonacci number 53316291173 and its prime divisors 953 and 55945741 have exactly the same number of decimal digits. %t A137574 Select[Fibonacci[Range[3,100]],IntegerLength[#]==Total[IntegerLength/@First/@FactorInteger[#]]&] (* _James C. McMahon_, May 30 2025 *) %Y A137574 Cf. A000045, A053409. %K A137574 nonn,base %O A137574 1,1 %A A137574 _Parthasarathy Nambi_, Apr 25 2008 %E A137574 a(21)-a(27) from _James C. McMahon_, May 30 2025