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 A159021 #13 Jan 08 2020 09:46:16 %S A159021 19,23,27,32,37,43,49,56,63,70,78,86,95,104,114,124,135,146,158,170, %T A159021 183,196,210,224,238,253,268,284,300,317,334,352,370,389,408,428,448, %U A159021 469,490,512,534,557,580,604,628,653,678,704,730,757,784,812,840,868,897,926,956,986,1017 %N A159021 a(0)=19; a(n) = a(n-1) + floor(sqrt(a(n-1))), n > 0. %C A159021 Row 3 in square array A159016. %C A159021 This sequence contains infinitely many squares. - _Philippe Deléham_, Apr 04 2009 %C A159021 Conjecture: The squares are of the form (7*2^k)^2 (see A005009). - _Vincenzo Librandi_, Apr 10 2009 %H A159021 Harvey P. Dale, <a href="/A159021/b159021.txt">Table of n, a(n) for n = 0..1000</a> %t A159021 NestList[#+Floor[Sqrt[#]]&,19,60] (* _Harvey P. Dale_, Jan 04 2013 *) %Y A159021 Cf. A028392, A005009. %K A159021 nonn %O A159021 0,1 %A A159021 _Philippe Deléham_, Apr 02 2009 %E A159021 More terms from _Vincenzo Librandi_, Apr 10 2009