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 A193714 #13 Apr 04 2025 04:17:48
%S A193714 1,3,5,8,10,12,14,16,19,21,24,26,28,31,33,36,38,40,43,45,48,50,53,55,
%T A193714 57,60,62,65,67,69,72,74,77,79,81,83,85,88,90,93,95,97,100,102,105,
%U A193714 107,109,112,114,117,119,122,124,126,129,131,134,136,138,141,143
%N A193714 Positions of squares (A000290) in the union of squares and triangular numbers (A005214).
%H A193714 Reinhard Zumkeller, <a href="/A193714/b193714.txt">Table of n, a(n) for n = 1..10000</a>
%F A193714 A010052(A005214(a(n))) = 1.
%F A193714 a(n) ~ c * n, where c = 1 + sqrt(2) = A014176 = 2.414213... . - _Amiram Eldar_, Apr 04 2025
%t A193714 With[{max = 4000}, Position[Union[Join[Accumulate[Range[Floor[(Sqrt[8*max + 1] - 1)/2]]], Range[Floor[Sqrt[max]]]^2]], _?(IntegerQ[Sqrt[#]] &)] // Flatten] (* _Amiram Eldar_, Apr 04 2025 *)
%o A193714 (Haskell)
%o A193714 import Data.List (elemIndex)
%o A193714 import Data.Maybe (fromJust)
%o A193714 a193714 n = a193714_list !! (n-1)
%o A193714 a193714_list =
%o A193714 map ((+ 1) . fromJust . (`elemIndex` a005214_list)) $ tail a000290_list
%Y A193714 Cf. A000290, A005214, A010052, A014176, A193715.
%K A193714 nonn
%O A193714 1,2
%A A193714 _Reinhard Zumkeller_, Aug 03 2011