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 A067815 #19 Nov 19 2024 06:03:05 %S A067815 1,1,1,2,1,2,1,2,3,1,1,3,1,1,3,4,1,2,1,4,1,2,1,4,5,1,1,1,1,5,1,1,1,1, %T A067815 5,6,1,2,3,2,1,6,1,2,3,2,1,6,7,1,1,1,1,1,1,7,1,1,1,1,1,1,7,8,1,2,1,4, %U A067815 1,2,1,8,1,2,1,4,1,2,1,8,9,1,1,3,1,1,3,1,1,9 %N A067815 a(n) = gcd(n, floor(sqrt(n))). %H A067815 Reinhard Zumkeller, <a href="/A067815/b067815.txt">Table of n, a(n) for n = 1..10000</a> %t A067815 a[n_] := GCD[n, Floor[Sqrt[n]]]; Array[a, 100] (* _Amiram Eldar_, Nov 19 2024 *) %o A067815 (Haskell) %o A067815 a067815 n = gcd n $ a000196 n -- _Reinhard Zumkeller_, Jul 08 2014 %o A067815 (PARI) a(n) = gcd(n, sqrtint(n)); \\ _Altug Alkan_, Dec 19 2017 %Y A067815 Cf. A000196, A073890, A075119. %K A067815 nonn,look %O A067815 1,4 %A A067815 _Reinhard Zumkeller_, Feb 08 2002