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 A106308 #12 Feb 16 2025 08:32:57 %S A106308 2,3,5,31,43,53,79,83,89,97,109,131,137,139,151,199,229,233,239,257, %T A106308 283,313,317,359,367,389,433,443,479,487,569,571,577,601,617,641,643, %U A106308 659,673,677,769 %N A106308 Primes that yield a simple orbit structure in 4-step recursions. %C A106308 Consider the 4-step recursion x(k) = (x(k-1) + x(k-2) + x(k-3) + x(k-4)) mod n. For any of the n^4 initial conditions x(1), x(2), x(3) and x(4) in Zn, the recursion has a finite period. When n is a prime in this sequence, all of the orbits, except the one containing (0,0,0,0), have the same length. %C A106308 For the prime 3 the orbit structure contains three orbits of length 1: (0,0,0,0), (1,1,1,1) and (2,2,2,2). %H A106308 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Fibonaccin-StepNumber.html">Fibonacci n-Step Number</a>. %Y A106308 Cf. A106286 (orbits of 4-step sequences). %K A106308 nonn %O A106308 1,1 %A A106308 _T. D. Noe_, May 02 2005, revised May 12 2005