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 A340497 #5 Jan 11 2021 13:21:41 %S A340497 1,6,16,21,56,61,71,76,216,221,231,236,271,276,286,291,856,861,871, %T A340497 876,911,916,926,931,1071,1076,1086,1091,1126,1131,1141,1146,3416, %U A340497 3421,3431,3436,3471,3476,3486,3491,3631,3636,3646,3651,3686,3691,3701,3706,4271,4276,4286 %N A340497 Index where 2*n first appears in A340488. %C A340497 A bisection of A340494. Note that there is a conjectured g.f. for A340494. %H A340497 N. J. A. Sloane, <a href="/A340497/b340497.txt">Table of n, a(n) for n = 0..4095</a> %Y A340497 Cf. A340488, A340494. %K A340497 nonn %O A340497 0,2 %A A340497 _N. J. A. Sloane_, Jan 11 2021