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 A118126 #10 Nov 25 2021 01:12:00 %S A118126 1,3,15,51,171,745,1057,3507,23205,50779,51475,97113,241887,593727, %T A118126 636291,1661215,6010095,6100953,8825911,22032619,24058237,71730273, %U A118126 84577003,98797723,119871675,255510487,380154649,404917765,704823889,910302427,1696449051,2565189555,9024827079 %N A118126 Lucky numbers (A000959) at which records in first differences (A031883) occur. %C A118126 An increasing subset of sequence A031884. %e A118126 a(4) = 51 since the 4th record value in the lucky number "first differences" sequence occurs A031883(14) = 12 which corresponds to lucky number A000959(14) = 51. %t A118126 lst = Range[1, 10^6, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; lst2 = {}; d = 0; Do[a = t[[n + 1]] - t[[n]]; If[a > d, d = a; AppendTo[lst, t[[n]]]], {n, 5286237}]; lst2 %Y A118126 Cf. A000959, A031883, A031884. %K A118126 nonn,more %O A118126 1,2 %A A118126 _Robert G. Wilson v_, May 12 2006 %E A118126 a(25)-a(29) from _Donovan Johnson_, Oct 23 2010 %E A118126 a(30) from _Donovan Johnson_, Jun 20 2011 %E A118126 a(31)-a(33) from _Kevin P. Thompson_, Nov 24 2021