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 A280774 #14 Mar 22 2017 14:52:41 %S A280774 1,3,6,10,13,23,27,30,34,38,48,54,62,65,69,86,90,94,103,120,127,131, %T A280774 135,139,144,148,161,165,185,197,211,255,258,262,275,286,290,300,311, %U A280774 319,330,334,350,354,358,367,375,379,399,414,420,427,443,447,453,457,465,486,500,504,530,534,549,555,559 %N A280774 Numbers k such that gcd(A280864(k), A280864(k+1)) = 1. %H A280774 N. J. A. Sloane, <a href="/A280774/b280774.txt">Table of n, a(n) for n = 1..25317</a> %Y A280774 Cf. A280864. %Y A280774 First differences give A283832. %K A280774 nonn %O A280774 1,2 %A A280774 _N. J. A. Sloane_, Jan 19 2017