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 A377032 #9 Oct 16 2024 09:20:20 %S A377032 1,3,405,625,1875,50625,354375,556875,658125,860625,961875,1164375, %T A377032 1468125,1500625,1569375,1873125,2075625,2176875,2379375,2683125, %U A377032 2986875,3088125,3391875,3594375,3695625,3720087,3999375,4201875,4501875,4505625,4910625,5113125,5214375,5416875,5518125,5720625 %N A377032 Odd numbers k such that A000045(k)/A000005(k) is an integer. %C A377032 Odd numbers k such that Fibonacci(k) is divisible by tau(k). %C A377032 Includes 15^4 * p for primes p > 5. %H A377032 Robert Israel, <a href="/A377032/b377032.txt">Table of n, a(n) for n = 1..250</a> %e A377032 a(3) = 405 is a term because 405 = 3^4 * 5 is odd, tau(405) = 10, and Fibonacci(405) = 1952132532477489958194625524584538730388053593825001030592563956919572392152809678530 is divisible by 10. %p A377032 filter:= proc(n) uses LinearAlgebra:-Modular; local t, Mt,dt; %p A377032 t:= numtheory:-tau(n); %p A377032 if t < 2^25 then Mt:= Mod(t, M, float[8]) else Mt:= Mod(t, M, integer) fi;; %p A377032 MatrixPower(t,M,n)[1,2] = 0 %p A377032 end proc: %p A377032 filter(1):= true: %p A377032 select(filter, [seq(i,i=1..600000,2)]); %Y A377032 Intersection of A160684 and A005408. %K A377032 nonn %O A377032 1,2 %A A377032 _Robert Israel_, Oct 14 2024