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 A102528 #4 Jul 12 2012 00:39:48 %S A102528 1,2,4,6,7,10,11,12,15,17,18,20,21,24,25,28,29,30,33,34,35,38,40,41, %T A102528 43,46,47,48,50,52,54,56,57,58,61,63,65,66,68,70,71,74,76,77,79,80,82, %U A102528 84,86,88,89,92,93,94,96,98,100,102,104,106,107,109,111,112,115,116,117 %N A102528 a(n)=least positive integer not a(k) or a(k)+floor(k/2) for any k<n. %e A102528 Let b(n)=n-th positive integer of the form a(k)+floor(k/2). Clearly a(1)=1, so b(1)=1, so a(2)=2, so b(2)=3, so a(3)=4 and so on. %Y A102528 Cf. A102529, A102530. %K A102528 nonn %O A102528 1,2 %A A102528 _Clark Kimberling_, Jan 13 2005