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 A238497 #21 Aug 02 2025 06:51:11 %S A238497 1,1,2,3,5,13,21,34,55,89,233,377,610,987,1597,4181,6765,10946,17711, %T A238497 28657,75025,121393,196418,317811,514229,1346269,2178309,3524578, %U A238497 5702887,9227465,24157817,39088169,63245986,102334155,165580141,433494437 %N A238497 Cubefree Fibonacci numbers. %H A238497 Carmine Suriano, <a href="/A238497/b238497.txt">Table of n, a(n) for n = 1..165</a> %F A238497 A010056(a(n)) * A212793(a(n)) = 1. - _Reinhard Zumkeller_, Feb 28 2014 %e A238497 a(21) = 75025 since 75025 = fib(25) = 5^2 * 3001 has no cubic factor. %t A238497 Select[Fibonacci@ Range@ 120, Max[Last /@ FactorInteger@ #] < 3 &] (* _Giovanni Resta_, Feb 27 2014 *) %o A238497 (Haskell) %o A238497 a238497 n = a238497_list !! (n-1) %o A238497 a238497_list = filter ((== 1) . a212793) $ tail a000045_list %o A238497 -- _Reinhard Zumkeller_, Feb 28 2014 %Y A238497 Cf. A000045, A061305. %Y A238497 Intersection of A004709 and A000045. %K A238497 nonn %O A238497 1,3 %A A238497 _Carmine Suriano_, Feb 27 2014 %E A238497 b-file corrected from _Giovanni Resta_, Feb 28 2014