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 A301561 #16 Oct 04 2021 08:11:36 %S A301561 610,987,10946,3524578,9227465,24157817,39088169,63245986,1836311903, %T A301561 7778742049,20365011074,591286729879,4052739537881,17167680177565, %U A301561 44945570212853,61305790721611591,420196140727489673,1500520536206896083277,6356306993006846248183 %N A301561 Sphenic Fibonacci numbers. %C A301561 Intersection of A000045 and A007304. There are 28 sphenic numbers among the first 200 positive Fibonacci numbers. %F A301561 A000045 INTERSECT A007304. %e A301561 610 is a term since it is a Fibonacci number that is a product of 3 distinct primes, 610=2*5*61, which makes it a sphenic number. %t A301561 Select[Fibonacci@Range[120], SquareFreeQ[#]&&PrimeNu[#]==3&] %o A301561 (PARI) for(n=1, 120, fn=fibonacci(n); issquarefree(fn)&&omega(fn)==3&&print1(fn ",")) %Y A301561 Cf. A000045, A007304, A061305 (squarefree Fibonaccis), A137563 (Fibonaccis with 3 distinct primes). %K A301561 nonn %O A301561 1,1 %A A301561 _Waldemar Puszkarz_, Mar 23 2018