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 A245070 #15 Jul 16 2014 06:31:34 %S A245070 3,2,2,3,2,2,4,2,2,3,2,2,3,2,2,3,2,2,4,2,2,3,2,2,3,2,2,3,2,2,4,2,2,3, %T A245070 2,2,3,2,2,3,2,2,4,2,2,3,2,2,3,2,2,3,2,2,4,2,2,3,2,2,3,2,2,3,2,2,4,2, %U A245070 2,3,2,2,3,2,2,3,2,2,4,2,2,3,2,2,3,2 %N A245070 Smallest positive non-divisor of the n-th Lucas number (A000032). %C A245070 This sequence seems to be cyclic with period 12, but the equivalent sequence for the Fibonacci numbers (A152727) is not. %C A245070 Lucas numbers modulo 12 are cyclic with period 24 and no 0 in the cycle (unlike Fibonacci numbers): 2, 1, 3, 4, 7, 11, 6, 5, 11, 4, 3, 7, 10, 5, 3, 8, 11, 7, 6, 1, 7, 8, 3, 11. It follows that this sequence is cyclic with period 12: 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2. - _Jens Kruse Andersen_, Jul 15 2014 %H A245070 Jens Kruse Andersen, <a href="/A245070/b245070.txt">Table of n, a(n) for n = 0..1000</a> %F A245070 For n >= 12, a(n) = a(n-12). - _Jens Kruse Andersen_, Jul 15 2014 %e A245070 a(6) = 4 because lucas(6) = 18, both 2 and 3 divide 18, but 4 does not. %o A245070 (PARI) lucas(n) = if(n==0, 2, 2*fibonacci(n-1)+fibonacci(n)); %o A245070 vector(1000, n, m=lucas(n-1); d=2; while(m%d==0, d++); d) %Y A245070 Cf. A000032, A152727. %K A245070 nonn %O A245070 0,1 %A A245070 _Colin Barker_, Jul 12 2014