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 A263225 #28 Sep 08 2022 08:46:14 %S A263225 1,60,240,600,660,768,1008,1200,1320,1800,1860,2160,2688,2736,3000, %T A263225 3300,3360,3888,4620,4800,5280,5520,5568,6120,6480,6720,6840,7320, %U A263225 7680,8208,8640,9000,9600,9720,10368,11160,12240,12288,13200,13248,13440,13680,13868,14400,15120,15360 %N A263225 Positive values of n such that A027961(n) is divisible by A000217(n). %C A263225 Is there a maximum value of a(n) - a(n-1)? %C A263225 A263161 is not a subsequence although they have many common terms. %C A263225 Terms that are not congruent to 0 (mod 6): 1, 13868, 16016, 34988, 158252, 196412, 313988, 1287788, 2056748, 2212412, 2542028, 2847260, 2951708, 6117548, 7538108, 7756988, 9056732, 9865628, ... . - _Robert G. Wilson v_, Oct 15 2015 %e A263225 For n = 1, A027961(1) = 1 is divisible by A000217(1) = 1. %e A263225 For n = 60, A027961(60) = 9062201101800 = 1830*4952022460, therefore it is divisible by A000217(60) = 1830. %t A263225 fQ[n_] := Mod[ Fibonacci[n + 1] + Fibonacci[n + 3] - 3, n (n + 1)/2] == 0; Select[ Range@ 16000, fQ] (* _Robert G. Wilson v_, Oct 15 2015 *) %o A263225 (PARI) for(n=1, 20000, if((fibonacci(n+3) + fibonacci(n+1)-3) % (n*(n+1)/2) == 0, print1(n", "))); %o A263225 (Magma) [n: n in [1..20000] | IsDivisibleBy(Lucas(n+2)-3,n*(n+1) div 2)]; // _Bruno Berselli_, Oct 19 2015 %Y A263225 Cf. A000204, A000217, A027961, A263161. %K A263225 nonn,easy %O A263225 1,2 %A A263225 _Altug Alkan_, Oct 12 2015