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 A183856 #14 Jun 04 2019 11:46:40 %S A183856 2,4,5,7,8,10,11,12,14,15,16,17,19,20,21,22,24,25,26,27,28,30,31,32, %T A183856 33,34,35,37,38,39,40,41,42,44,45,46,47,48,49,50,52,53,54,55,56,57,58, %U A183856 59,61,62,63,64,65,66,67,68,70,71,72,73,74,75,76,77,78,80,81,82,83,84,85,86,87,88,89,91,92,93,94,95,96,97,98,99,100,102,103,104,105,106 %N A183856 n+floor(sqrt(3n-2)); complement of A143975. %H A183856 Robert Israel, <a href="/A183856/b183856.txt">Table of n, a(n) for n = 1..10000</a> %F A183856 a(n+1) - a(n) = 2 if n is in A000212, 1 otherwise. - _Robert Israel_, Jun 04 2019 %p A183856 seq(seq(i+k,i=ceil((k^2+2)/3) .. ((k+1)^2+1)/3),k=1..10); # _Robert Israel_, Jun 04 2019 %t A183856 Array[#+Floor[Sqrt[3#-2]]&,100] (* _Harvey P. Dale_, Mar 15 2013 *) %Y A183856 Cf. A000212, A143975. %K A183856 nonn,easy %O A183856 1,1 %A A183856 _Clark Kimberling_, Jan 07 2011