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 A183570 #12 Jan 19 2019 20:30:20 %S A183570 1,2,3,5,6,7,8,9,11,12,13,14,15,16,17,19,20,21,22,23,24,25,26,27,29, %T A183570 30,31,32,33,34,35,36,37,38,39,41,42,43,44,45,46,47,48,49,50,51,52,53, %U A183570 55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,109 %N A183570 a(n) = n + floor(sqrt(n + 1)). %p A183570 A183570 := proc(n) n+floor(sqrt(n+1)) ; end proc: %p A183570 seq(A183570(n),n=0..100) ; # _R. J. Mathar_, Jan 29 2011 %Y A183570 Cf. A028552 (complement, except for initial term). %K A183570 nonn,easy %O A183570 0,2 %A A183570 _Clark Kimberling_, Jan 05 2011 %E A183570 All terms corrected by _R. J. Mathar_, Jan 29 2011